bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantum kinetic dust acoustic waves in arbitrary degenerate quantum dusty plasma
Authors: Ahmad Mushtaq , Fahad S. , Ur Rahman Waheed
Published: January 2020

Using kinetic formulation with a quantum plasma dynamic approach, dust acoustic waves (DAWs) in three component non-relativistic, isotropic, unmagnetized, and collisionless quantum dusty plasma are analytically analyzed. Electrons are considered as quantum mechanical, following the Fermi–Dirac distribution, while ions and dust are considered as classical, obeying Maxwell–Boltzmann statistics. The longitudinal response function, in terms of susceptibility tensors, is derived and divided into two parts, i.e., dispersion relation (real part) and Landau damping (imaginary part). The dispersion relations and Landau damping rates are analyzed with the effect of the arbitrary degree of temperature degeneracy and quantum recoil. Two cases of the DAWs are discussed regarding the arbitrary degeneracy, which are nearly non-degenerate and nearly degenerate quantum plasmas. The dispersion relations and Landau damping rates for DAWs in both cases are examined analytically and numerically, using the data of semiconductor quantum wells and dense astrophysical plasmas.
Measurement of the refractive index of an Er3+:YAG crystal melt
Authors: Bufetova G. A. , Kashin V. V. , Rusanov S. Ya. , Seregin V. F. , Tsvetkov V. B.
Published: January 2020

A new method for measuring the refractive index of crystals and melts at high temperatures is presented. The refractive index of an Er3+:YAG crystal melt is determined during the laser-heated pedestal growth process close to the melting point. The main idea is to use the maximal difference in the intensities of two polarizations of thermal radiation passing the melt-air interface. From the Fresnel equations, it follows that this difference is almost proportional to the refractive index. Angular diagrams of the thermal radiation of the melt for two polarizations are analyzed. The obtained value of the refractive index of the Er3+:YAG melt is n = 1.84 ± 0.01 in the wavelength range of 550–620 nm.
Hard x-ray photoemission spectroscopy of rhenium substituted higher manganese silicides
Authors: Matsunami M. , Iizuka T. , Ghodke S. , Yamamoto A. , Miyazaki H. , Takeuchi T.
Published: January 2020

We have investigated the electronic structure of a potential thermoelectric material, higher manganese silicide, and its solid solutions with supersaturated Re by means of hard x-ray photoemission spectroscopy. The unusual Re substitution dependence of thermoelectric properties in the higher manganese silicide, reducing the electrical resistivity without altering the Seebeck coefficient, can be explained in terms of the variation of the density of states at the Fermi level and its energy derivative. Such an electronic structure variation contributes to an improvement in the thermoelectric performance in combination with the suppressed thermal conductivity.
Study of the beam-wave interaction of a 0.34-THz confocal waveguide gyro-TWT with confocal beam
Authors: Zhipeng Wang , Yu Sheng , Chen Rutai , Li Qiao
Published: January 2020

In this paper, in order to enhance the efficiency of the confocal gyrotron travelling wave tube (confocal gyro-TWT), the confocal beam is first introduced based on the field distribution of the operating mode in the confocal waveguide. Besides, a confocal gyro-TWT with a confocal beam operating at 0.34 THz is simulated and designed based on linear and nonlinear theories. It is verified that the confocal beam can enhance the interaction efficiency and output power significantly through simulation. In addition, the effects of electron beam parameters on output power are also analyzed in this paper. The simulation results indicate that the confocal gyro-TWT can operate at TE06 stably with an output power of 17.3 kW when the beam voltage is 60 kV, beam current is 2 A, input power is 40 mW, and transverse velocity spread is 5%. The corresponding frequency and interaction efficiency are 0.34 THz and 14.4%, respectively.
Spin Hall angle and spin diffusion length of permalloy
Authors: Huang Yi-Hsiang , Weng Yi-Chien , Liang Chi-Te , Lin J. G.
Published: January 2020

The inverse spin Hall effect (ISHE) in a ferromagnetic material (FM) has been attracting much attention due to its importance in spintronic applications. ISHE, which converts a spin current into a charge current, is an effective method for detecting spin currents. In this work, we report the observation of ISHE on permalloy (Py) thin films under the ferromagnetic resonance condition. The values of the spin Hall angle (θSHE) and the spin diffusion length (λPy) for Py are determined to be 0.034% and 7.0 nm, respectively. The values of θSHE and λPy are investigated for the first time with spin pumping techniques for a FM.
Photoinduced Hall effect and transport properties of irradiated 8-Pmmn borophene monolayer
Authors: Napitu B. D.
Published: January 2020

Electronic properties of a borophene monolayer irradiated with polarized light are investigated within the average Hamiltonian approximation together with the van Vleck canonical perturbation. It is shown that varying the intensity of circularly polarized light leads to a gap opening in the single- and two-particle excitations signaling a transition from a metallic to insulating state. Simultaneously, the topology of band structure moves away from a π Berry phase, and the transversal conductivity is quantized in units of e2/h, signifying the photoinduced Hall effect. The application of linearly polarized light on borophene, on the other hand, leaves the topology of band structure intact. The interaction between electrons and photons amounts to renormalizing Fermi velocities and its signature can be traced in the density of states and longitudinal conductivity. I elaborate the discussion by examining ballistic transport of a borophene nanostructure with single and double potential barrier. In both setups, the transmission function exhibits Klein tunneling which is asymmetrically distributed with respect to the normal incidence following the anisotropy of the Fermi surface. Analysis of conductance indicates that electric signals can be enhanced and suppressed by intensity as well as helicity of light, suggesting that irradiated borophene with single and double barrier is an appealing platform for photosensitive devices.
Magnetic field dependence of the martensitic transition and magnetocaloric effects in Ni49BiMn35In15
Authors: Aryal Anil , Dubenko Igor , Talapatra Saikat , Granovsky Alexander , Lähderanta Erkki , Stadler Shane , Ali Naushad
Published: January 2020

The structural, magnetic, and magnetocaloric properties of the Bi-doped Heusler alloy Ni49BiMn35In15 have been investigated using room temperature X-ray diffraction (XRD) and magnetization measurements in a temperature interval of 5-400 K. The alloy at room temperature was found to be in a mixture of a high temperature austenite phase (AP) and a low temperature martensite phase (MP). A drastic shift in the martensitic transition temperature at the rate of 16 K/T from 197 K to lower temperatures was observed. A kinetic arrest phenomenon of the AP was observed in the magnetization and electrical resistivity measurements during field-cooled (FC) measurements at 5T. A metamagnetic behavior characterized by a jump in magnetization in the isothermal M(H) curves near TM was observed. The maximum value of the magnetic entropy change and refrigerant capacity at Curie temperature were found to be 5.5 Jkg-1K-1 and 312 Jkg-1 for μoΔH = 5T, respectively. A large magnetoresistance value of -56% was found near the martensitic transition.
Combining steady-state with frequency and time domain data to quantitatively analyze charge transport in organic light-emitting diodes
Authors: Jenatsch S. , Züfle S. , Blülle B. , Ruhstaller B.
Published: January 2020

Typically, organic light-emitting diodes (OLEDs) are characterized only in steady-state to determine and optimize their efficiency. Adding further electro-optical measurement techniques in frequency and time domain helps to analyze charge carrier and exciton dynamics and provides deeper insights into the device physics. We, therefore, first present an overview of frequently used OLED measurement techniques and analytical models. A multilayer OLED with a sky-blue thermally activated delayed fluorescent dopant material is employed in this study without loss of generality. Combining the measurements with a full device simulation allows one to determine specific material parameters such as the charge carrier mobilities of all the layers. The main part of this tutorial focuses on how to systematically fit the measured OLED characteristics with microscopic device simulations based on a charge drift-diffusion and exciton migration model in 1D. Finally, we analyze the correlation and sensitivity of the determined material parameters and use the obtained device model to understand limitations of the specific OLED device.
Molecular dynamic simulation of tool groove wear in nanoscale cutting of silicon
Authors: Liu Changlin , Chen Xiao , Zhang Jianguo , Zhang Junjie , Chu Jianning , Xiao Junfeng , Xu Jianfeng
Published: January 2020

Tool wear is one of the bottlenecks that decrease the machinability of hard and brittle materials in single point diamond turning (SPDT). Specifically, a microgroove generated on the cutting edge is an important character of tool wear, which leads to the formation of subcutting edges and facilitates the ductile to brittle transition in machining. However, the mechanism of the groove wear influence on the machined workpiece, especially the subsurface damage, is not clear just by the experimental investigations. In this paper, molecular dynamic simulations were carried out to explore the influence of groove wear on workpiece subsurface damage in SPDT of single crystal silicon. The propagation of grooves was also investigated by discussion of the stress and temperature distribution on the cutting edge. The Weierstrass-Mandelbrot function was adopted to set up groove wear on the tool flank face. It is concluded that grooves improve the atomic flowing ability and the plastic deformation in the workpiece. Moreover, the grooves can also cause polycrystal transition in the workpiece subsurface. The thickness of the subsurface damaged region is increased when groove wear becomes severe. This study contributes to the understanding of the details involved in the interaction between tool groove wear and workpiece, which is advantageous to improve the machined surface quality.
The calculation of magnetic domain and magnetostriction in stressed grain-oriented silicon steel
Authors: He Zhenghua , Sha Yuhui , Zhao Zipeng , Zhang Fang , Yang Yongjie , Li Guobao , Zuo Liang
Published: January 2020

A calculation model for magnetic domain configuration and magnetostriction in grain-oriented silicon steel under tension stress is proposed. The surface lancet and transverse domains in demagnetization and magnetization states are calculated as a function of grain orientation and tension stress. Magnetostriction is calculated by incorporating the critical conditions for disappearance and reappearance of the transverse domain during the magnetization process. The magnetic domain and magnetostriction vary obviously with tension stress and misorientation angle, especially in the ranges of 5–20 MPa and 1°–5°. Negative magnetostriction is quantitatively evaluated in terms of the contribution of the reappeared transverse domain. The calculation model can accurately characterize the magnetostriction of grain-oriented silicon steel under tension stress based on the normal distribution of misorientation angle.
Nonlinear coupling of electromagnetic and electron acoustic waves in multi-species degenerate astrophysical plasma
Authors: Shatashvili N. L. , Mahajan S. M. , Berezhiani V. I.
Published: January 2020

Nonlinear wave-coupling is studied in a multispecies degenerate astrophysical plasma consisting of two electron species (at different temperatures): a highly degenerate main component plus a smaller classical relativistic flow immersed in a static neutralizing ion background. It is shown that the high frequency electromagnetic waves through their strong nonlinear interactions with the electron-acoustic waves [sustained by a multielectron component (degenerate) plasma surrounding a compact astrophysical object] can scatter to lower frequencies so that the radiation observed faraway will be spectrally shifted downward. It is also shown that, under definite conditions, the electromagnetic waves could settle into stationary solitonic states. It is expected that the effects of such structures may persist as detectable signatures in forms of modulated micropulses in the radiation observed far away from the accreting compact object. Both these effects will advance our abilities to interpret the radiation coming out of the compact objects.
Intonation across two border areas in the North Andean region: Mérida
(Venezuela) and Medellin (Colombia)
Authors: Díaz Chaxiraxi , Dorta Josefa , Mora Elsa , Muñetón Mercedes
Published: January 2020

The Andes mountain system serves as a natural border throughout
several South American countries. This research takes place in the region known
as the Northern Andes, in two of the most important cities of the Venezuelan and
Colombian Andes: Mérida, State of Mérida, and Medellin, Department of
Antioquia.

The main purpose of this study is to establish intonation
similarities and differences between these two Andean cities. As a preliminary
study, part of the AMPER Project, it examines the F0 as a melodic support. The
study has been conducted according to the parameters established in the
above-mentioned project.

The intention of this research is twofold: First, to accomplish
one of the main AMPER goals of performing comparative studies among diverse
Romance languages and its varieties; and secondly, to establish possible
relationships and differences among language varieties that are in contact,
despite being separated by borderlines.
Prosody: A feature of languages or a feature of speakers?
Authors: Muñiz-Cachón Carmen
Published: January 2020

Social situations of language coexistence have resulted in linguistic manifestations of bilingualism and
diglossia, including linguistic interference, lexical loans and code switching.

What role does prosody play in social bilingualism? In other words, when contact between different languages is
not restricted to the individual but affects an entire speech community, does a dominant prosody exist? Does prosody vary among
different linguistic varieties?

In order to find an answer to these questions, we hereby show the results of a research project on the prosodic
features of Asturian and Castilian spoken in the centre of Asturias. This experimental study is based on the speech of four
informants from Oviedo – two men and two women – two of which speak Castilian, while the other two speak Asturian.
Stress clash in Spanish, Catalan, and Friulian from a prosodic perspective
Authors: Martínez Celdrán Eugenio , Roseano Paolo
Published: January 2020

In several languages, two stresses cannot appear adjacently in the speech chain, and a variety of solutions have been found to be used to resolve this disfavored juxtaposition. According to various different authors, a common strategy for solving stress clash is the non-realization of the first stress and, typically, a transfer of all stress parameters to the pre-tonic syllable.

This study aims to describe how stress clash is solved in three Romance languages (Spanish, Catalan, and Friulian) and two sentence-types (broad focus statements and information-seeking yes-no questions). The first two languages behave similarly, insofar as length and loudness are not stress-supporting parameters, and F0maintains the general patterns of the type of sentence. Friulian stands out because length is the main stress parameter and tonic syllables are significantly longer, even when there is a stress clash. F0also follows the general sentence type pattern, with one exception: declarative sentences in NP1, where the pre-tonic syllable is always higher than its corresponding tonic.
F0 declination of intonation groups in Spanish and in Mandarin Chinese
Authors: Yao Junming
Published: January 2020

Mandarin Chinese and Spanish are the first two languages in the world by number of speakers. The interaction between speakers and thus between the two languages increases day by day. There are more and more Chinese students who study Spanish and Spanish students who study Chinese. At the same time, difficulties arise from the teaching-learning process, particularly with regard to phonetics, and more specifically the intonation, as they are two typologically-different languages. However, there exist very few comparative studies between them.

This article seeks to explore the global declination of intonation groups in Spanish and Mandarin Chinese and we found similarities and differences between these two languages. To do this, we created a corpus of 278 isolated and unmarked sentences and 140 neutral paragraphs in Mandarin Chinese (totally 651 sentences), while in Spanish we used data from previous studies. The corpus was recorded by nine native speakers, three men and six women.

We approached this study from a phonetic point of view and used the Garrido model (Garrido 1996,2001,2010) to compare the declination effect on the two languages according to different factors such as sentence type, the position of the intonation group within the utterance and length of the group.

We also proposed for future study some possible methods for teaching Chinese and Spanish intonation as a second language.
Is the 'dark' still dark? The evolution of dark tourism and pilgrimage destinations.
Authors: Bİdecİ M.
Published: January 2020

This chapter outlines the historical transformation of dark tourism sites from the premodern era to the present. This is done through discussing the idea of sacred journeys through pilgrimage and dark tourism. The chapter also examines the growth of dark tourism through different historical phases, and in so doing distinguishes between different 'shades' of dark tourism, and questions whether dark tourism is really 'dark'.
Museums as in populo dark tourism sites: a case study of Visitor experience.
Authors: Bond N. , Carr A. , Comtesse D.
Published: January 2020

This chapter examines how both indigenous and non-indigenous visitors to the Western Australian Museum (Perth, Western Australia) both connected with and authenticated their experiences of the museum's Aboriginal gallery (Katta Djinoong), and the emotional responses and learning that flow from those experiences. It is shown that museums that confront colonization and the subjugation of Aboriginal peoples can, and should, be considered as places of in populo dark tourism.
Finding roots: pop culture pilgrimage and the affective geographies of Kunta Kinteh Island.
Authors: Wright K.
Published: January 2020

This chapter examines how the transmedia narrative of Roots: The Saga of an American Family (a novel that was later adapted into two TV mini-series) has become entangled with the very real physical space of Kunta Kinteh Island, a dark tourist site in the Gambia River where millions of enslaved people were tortured and died. After more fully examining the back story of Roots, the rest of the chapter uses a non-representational approach to the study of place to frame the author's own experience of travelling to Kunta Kinteh Island and observing both the site and the tourismification of this 'factional' heritage.
Borough of the dead: the weight of hip hop's history and tourism's dark pilgrimage to the Bronx.
Authors: Donica J.
Published: January 2020

This chapter focuses on both dark tourism and pilgrimage as they coalesce in the Bronx around hip hop - the defining music genre and period of history for the borough - and how managers of planned sites that address this history are attempting to address the range of expectations that visitors will bring.
Drug use and HIV Medication Adherence in People Living with HIV
Authors: Sohler Nancy , Slawek Deepika , Earnshaw Valerie , Jost John , Lee Alice , Mancini John , Mompremier Arielle , Cunningham Chinazo O.
Published: January 2020

Background

Opioid and cocaine use epidemics continue to be substantial in the United States and intersect with the HIV epidemic. Antiretroviral medication (ARV) adherence is critical for optimum HIV outcomes. While previous research explored harm reduction strategies to prevent HIV spread for people who use drugs (PWUD), little is known about strategies used by PWUD living with HIV to maintain ARV adherence.

Methods

We explored whether PWUD modify their drug use explicitly to maintain ARV adherence, and identified factors associated with this process. We conducted 23 semi-structured interviews. Data were analyzed using a modified framework analysis approach.

Results

Participants had a mean age of 54 years and were predominantly male (70%) and non-Hispanic black (65%). Most described periods of being able to adhere to ARVs while still using drugs, difficulty adhering to ARVs while using drugs, and abstinence/near abstinence from drug use. In exploring factors that influenced changes in drug use and ARV adherence behaviors, we noted consistent acknowledgment of the roles of family, partners, or providers.

Conclusions

PWUD living with HIV often modify their drug use to improve ARV adherence. Providers caring for this population might consider family or group education models to encourage harm reduction to improve outcomes.
Harmful Drinking, Tobacco, and Marijuana use in the 2000–2015 National Alcohol Surveys: Examining Differential Trends by Sexual Identity
Authors: Drabble Laurie A. , Mericle Amy A. , Karriker-Jaffe Katherine J. , Trocki Karen F.
Published: January 2020

Background

Population-based surveys document disparities in substance use among sexual minorities compared to heterosexuals, but few studies examine changes over time. This study compared changes in harmful drinking (including alcohol use disorders and high-intensity drinking), tobacco use, marijuana use, and simultaneous marijuana and alcohol co-use between heterosexual and sexual minority adults over a 15-year period.

Methods

Gender-stratified logistic regression analyses using 4 waves of cross-sectional data from the National Alcohol Survey (2000, 2005, 2010, and 2015) were conducted to test overall trends over time and differences by sexual identity, as well as the interaction between survey year and sexual identity.

Results

Among women, significant effects for sexual identity were present in all models, reflecting greater odds of use among sexual minorities across waves. Among men, significant effects for sexual identity were found for high-intensity drinking (reflecting less use among sexual minorities) as well as marijuana use and marijuana and alcohol co-use (reflecting more use among sexual minorities). For women and men, tobacco use generally decreased and both marijuana use and simultaneous marijuana and alcohol co-use increased during the study period. Although trends were largely driven by heterosexual respondents, only one instance of an interactive effect was found; reports of harmful drinking were generally stable over time among heterosexual women, but higher and more variable over time among sexual minority women.

Conclusions

Findings highlight that differences in patterns of substance use by sexual identity persist and underscore the need for screening, prevention, and intervention, particularly for sexual minority women.
Law and Politics in the Inter-American System
Authors: Sandholtz Wayne , Padilla Mariana Rangel
Published: January 2020

The Inter-American Human Rights System takes into account domestic political contexts in ways that sometimes have not been fully recognized. International human rights courts face a tension between the goal of expanding rights and the need to gain legitimacy with domestic constituencies. Cases involving national amnesty laws have posed this dilemma in acute fashion in the Inter-American System. An analysis of those cases and their domestic political contexts shows how the Commission and the Court have taken into account domestic circumstances, the first through the timing of referrals and the second through the Court’s jurisprudence.
Phase evolution of ultra-thin Ni silicide films on CF4 plasma immersion ion implanted Si
Authors: Zhao Lan-Tian , Liu Mingshan , Ren Qing-Hua , Liu Chen-He , Liu Qiang , Chen Ling-Li , Spiegel Yohann , Torregrosa Frank , Yu Wenjie , Zhao Qing-Tai
Published: January 2020

We present a systematic study on the effects of CF4 plasma immersion ion implantation (PIII) in Si on the phase evolution of ultra-thin Ni silicides. For 3 nm Ni, NiSi2 was formed on Si substrates with and without CF4 PIII at temperature as low as 400 °C. For 6 nm Ni, NiSi was formed on pure Si, while epitaxial NiSi2 was obtained on CF4 PIII Si. The incorporation of C and F atoms in the thin epitaxial NiSi2 significantly reduces the layer resistivity. Increasing the Ni thickness to 8 nm results in the formation of NiSi, where the thermal stability of NiSi, the NiSi/Si interface and Schottky contacts are significantly improved with CF4 PIII. We suggest that the interface energy is lowered by the F and C dopants present in the layer and at the interface, leading to phase evolution of the thin Ni silicide.
Temporal trends in handgrip strength for older Japanese adults between 1998 and 2017
Authors: Tomkinson G R , Kidokoro T , Dufner T , Noi S , Fitzgerald J S , Mcgrath R P
Published: January 2020

Objective

to estimate temporal trends in handgrip strength (HGS) for older Japanese adults between 1998 and 2017.

Design and methods

adults aged 60–79 years were included. Annual nationally representative HGS data (n = 176,449) for the 19-year study period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in mean HGS were estimated by sample-weighted regression models relating the year of testing to mean HGS. National trends in absolute, percent and standardised HGS were estimated by a post-stratified population-weighting procedure. Temporal trends in variability were estimated as the ratio of coefficients of variation (CVs).

Results

collectively, there was a small improvement in mean HGS of 1.4 kg (95% confidence interval [CI]: 1.3–1.5), 4.5% (95%CI: 4.3–4.7) or 0.27 standard deviations (95%CI: 0.26–0.28) between 1998 and 2017. The rate of improvement progressively increased over time, with more recent values (post-2008) 1.5-fold larger than earlier values. Gender- and age-related temporal differences were negligible. Variability in HGS declined substantially over time (ratio of CVs [95%CI]: 0.88 [0.86–0.90]), with declines 1.9-fold larger in women compared to men and 1.7-fold larger in 70- to 79-year-olds compared to 60- to 69-year-olds.

Conclusions

there has been a small, progressive improvement in mean HGS for older Japanese adults since 1998, which is suggestive of a corresponding improvement in strength capacity. The substantial decline in variability indicates that the improvement in mean HGS was not uniform across the population.
Establishing a Satellite Transfusion Service Within an Academic Medical Center
Authors: Murphy Colin H , Lim Albert Y , Chua Lee , Shan Hua , Goodnough Lawrence T , Virk Mrigender S
Published: January 2020

Objectives

Increasingly complex medical care requires specialized transfusion support close at hand. Hospital growth can necessitate expansion of blood bank services to new locations to ensure rapid delivery of blood products. We describe the opening of a new satellite transfusion service designed to serve the needs of a pediatric hospital.

Methods

Institutional transition teams and stakeholders collaborated to discuss options for providing blood at a new pediatric hospital. A staffed satellite transfusion service met the diverse needs of multiple services and was considered a compromise between a full new transfusion service and automated solutions.

Results

Initial challenges in establishing the laboratory included regulatory uncertainty and interactions between two hospitals’ information technology services. Laboratory scientist staffing and actual use required adapting the satellite service to an emergency release–only model.

Conclusions

A flexibly staffed satellite transfusion service met the most urgent needs of a pediatric hospital expansion. Review of implementation revealed potential process improvements for future expansions, including comprehensive routine and massive transfusion simulations. The challenges experienced in supplying staff and specialized blood products track with national trends. Other institutions may consider establishing a satellite transfusion service in the context of both increasingly sophisticated automated solutions and complex blood needs.
Evaluation of the Reticulocyte Production Index in the Pediatric Population
Authors: Bracho Fernando J , Osorio Ignacio A
Published: January 2020

Objectives

Since hematologic values vary with age in children, we evaluated the agreement between the “traditional” reticulocyte production index (RPI) and an RPI by age (RPI/A)–adjusted normal values.

Methods

A retrospective, observational, and analytical study was performed on CBCs of children with anemia younger than 18 years. The agreement and clinical repercussions of the RPI values were analyzed with an RPI/A developed with theoretical values for different ages.

Results

A total of 5,503 tests were analyzed and no systematic error between the two indices was found; however, there were significant proportional differences at higher values that resulted in lower RPI/A in children younger than 15 days and higher RPI/A in children aged 15 days and older. No agreement was observed at any age. The proportion of arregenerative anemia diagnosed using RPI/A was higher in children younger than 15 days and lower in those 15 days and older.

Conclusions

RPI is not an adequate tool for evaluating the erythropoietic capacity of bone marrow in the pediatric population. The disagreement between the results can be explained by the difference in normal hematologic values between children and adults.
Long-term outcomes of clinical and pathological-staged T3 N3 esophageal cancer
Authors: Kamarajah S K , Newton N , Navidi M , Wahed S , Immanuel A , Hayes N , Griffin S M , Phillips A W
Published: January 2020

Locally advanced esophageal cancer is associated with poor long-term survival. Pre- and post-treatment stages may differ because of neoadjuvant therapy and inaccuracies in staging. The aim of this study was to determine the outcomes of patients staged with clinical T3 N3 and pathological T3 N3 carcinoma of the esophagus and determine differences between the groups. Consecutive patients from a single unit between 2010 and 2018 were included with either clinical (cT3 N3) or pathological (pT3 N3) esophageal cancer. Outcomes were compared between patients that underwent esophagectomy with or without neoadjuvant treatment and those patients staged cT3 N3 treated non-surgically (NSR). Patients were staged using the TNM 8. This study included 156 patients, 63 patients were staged cT3 N3 initially and had NSR treatment, only three of these had radical treatment. Of the remaining 93 patients who underwent esophagectomy, 34 were initially staged as cT3 N3, 54 were found to be pT3 N3 having been staged earlier initially, and five were unchanged before and after treatment. Median overall survival (OS) for surgical cT3 N3 patients was significantly longer than pT3 N3 and NSR (median: NR vs 19 vs 8 months, P < 0.001). Twenty-seven patients with cT3 N3 had lower staging following treatment, while three had a higher stage. T3 N3 disease carries a poor prognosis. Within this cohort, cT3 N3 disease treated surgically has a high 5-year OS suggesting possible over-staging and stage migration due to neoadjuvant therapy. Those not having surgery, have a dismal prognosis. The impact of neoadjuvant treatment cannot be predicted and, current staging modalities may be inaccurate. Clinical stage should be used with caution when counseling patients regarding management and prognosis.
OP02 Impact of therapeutic strategies on intestinal resection rate in paediatric inflammatory bowel diseases: A population-based cohort study over a 24-year period (1988–2011)
Authors: Ley D , Leroyer A , Dupont C , Sarter H , Bertrand V , Spyckerelle C , Guillon N , Pariente B , Savoye G , Turck D , Gower-Rousseau C , Fumery M
Published: January 2020

Background

Few data are available at the population level on the impact of the changes in therapeutic strategies over the last decades on inflammatory bowel diseases (IBD) long-term outcomes. We have evaluated the impact of immunosuppressants (IS) and anti-TNF introduction on intestinal resection rate, hospitalisation, and Crohn’s disease (CD) behaviour progression in a large population-based paediatric-onset IBD cohort.

Methods

Paediatric-onset IBD (<17 years) were issued from a prospective population-based study in France between 1988 and 2011 and were retrospectively followed until 2013. Risks for intestinal resection, hospitalisation and complicated CD behaviour (stricturing or penetrating) were compared between three diagnostic periods: 1988–1993 (P1), 1994–2000 (P2) and 2001–2011 (P3) using Kaplan–Meier survival analyses.

Results

One thousand and sixty-one patients diagnosed with CD (n = 800) or ulcerative colitis (UC, n = 261) were followed up during a median of 8.9 years (IQR: 5.0–14.7). Median age at diagnosis was 14.3 years (IQR: 11.8–16.0) and half of patients were female (n = 530, 50%). Over time, in CD, the IS and anti-TNF exposure rate increased from, respectively, 32% (P1) to 75% (P3) and from 0% (P1) to 51% (P3) at 5 years. In UC, IS and anti-TNF exposure increased from, respectively, 9% (P1) to 65% (P3) and from 0% (P1) to 40% (P3) at 5 years. In parallel, risk for intestinal resection at 5 years significantly declined in CD (P1: 35%, P2: 30%, P3: 20%, p < 0.05). No significant change in 5-year colectomy risk in UC was observed (P1: 14%, P2: 19%, P3: 9%, p = 0.08). Exposure to corticosteroid at 5 years of diagnosis did not change over time (P1: 10%, P2: 10%, P3: 8%, p = 0.54). Risk for IBD-flare-related hospitalisation at 5 years was similar over time in CD (P1: 43%, P2: 45%, P3: 43%, p = 0.60) and UC (P1: 31%, P2: 46%, P3: 52%, p = 0.10). Progression to a complicated behaviour in CD at 5 years did not change over time (P1: 31%, P2: 33%, P3: 25%, p = 0.20).

Conclusion

In parallel with the increased use of IS and anti-TNF agents, risk for intestinal resection within 5 years after diagnosis decreased in paediatric CD, whereas risks for flare-related hospitalisation and behaviour progression remained unchanged over a 24-year period.
OP04 Long-term outcomes after ileocolonic resection in Crohn’s disease according to the severity of early endoscopic recurrence
Authors: Hammoudi N , Auzolle C , Tran Minh M L , Boschetti G , Bezault M , Buisson A , Pariente B , Treton X , Seksik P , Fumery M , Le Bourhis L , Nancey S , Allez M
Published: January 2020

Background

Early ileocolonoscopy within the first year after surgery is the gold standard to evaluate post-operative recurrence after ileocolonic resection for Crohn’s disease (CD). The aim of the study was to evaluate the association between lesions at ileocolonoscopy 6 months after surgery and long-term outcomes.

Methods

The REMIND group conducted a prospective multicentre study. Patients operated for ileal or ileocolonic CD were included. An ileocolonoscopy was performed 6 months after surgery. An endoscopic classification separating anastomotic and ileal lesions was built (Ax for anastomotic lesions; Ix for neo-terminal ileum lesions evaluated according to the Rutggerts score). Clinical relapse was defined by CD-related symptoms confirmed by imaging, endoscopy or therapeutic intensification, CD-related complication or subsequent surgery.

Results

A total of 225 patients were included. Long-term data were available for 193 patients (86%). Median follow-up was 3.82 years (IQR:2.56–5.41) from surgery. Median clinical recurrence-free survival was 47.6 months. Clinical recurrence-free survival was significantly shorter in patients with ileal lesions at early post-operative endoscopy whatever their severity (I1 or I2I3I4) compared with patients without (I0) (median survivals: 68.5, 33.0 and 39.1 months, respectively, for I0, I1 and I2I3I4; I0 vs. I2I3I4: p = 0.0003; I0 vs. I1: p = 0.0008 and I1 vs. I2I3I4: p = 0.43). Patients with at least semi-circumferential anastomotic ulcerations (A2 or A3) had more anastomotic occlusive manifestations than patients without (A0 or A1) (A0 vs. A2A3: p = 0.01; A0 vs. A1: p = 0.83; A1 vs. A2A3: p = 0.05).

Conclusion

A classification separating anastomotic and ileal lesions might be more appropriate to define post-operative endoscopic recurrence. Patients with ileal lesions, including mild ones (I1), could beneficiate from treatment step up to improve long-term outcome.
OP14 Risk of colorectal cancer diagnosis and colorectal cancer mortality in Crohn’s disease: A Scandinavian population-based cohort study
Authors: Olen O , Erichsen R , Sachs M C , Pedersen L , Halfvarson J , Askling J , Ekbom A , Sørensen H T , Ludvigsson J F
Published: January 2020

Background

Crohn’s disease (CD) is a risk factor for colorectal cancer (CRC). Earlier studies reflect older treatment and surveillance strategies, and most have studied incident CRC without addressing potential lead-time and surveillance biases. Such bias can be reduced by examining tumour stage-adjusted CRC incidence and CRC mortality. We aimed to assess risks of CRC mortality and incident CRC among patients with CD compared with the general population.

Methods

Nationwide register-based cohort study during 1969–2017 of 47,035 patients with CD in Denmark (n = 13,056) and Sweden (n = 33,979), compared with 463,187 general population reference individuals, matched for sex, age, calendar year, and place of residence. We used Cox regression to estimate hazard ratios (HRs) for incident CRC and CRC mortality. In a multistate model, assessing competing events during follow-up (CRC diagnosis, CRC death, other death), we also took a tumour stage into account.

Results

During 1969–2017, 499 patients with CD developed CRC, corresponding to an adjusted HR of 1.40 [95% confidence interval (CI) 1.27–1.53]. We observed 296 (0.47/1000 person-years) deaths from CRC in patients with CD compared with 1968 (0.31/1000) in reference individuals [HR 1.74 (95% CI 1.54–1.96)]. CD patients diagnosed with CRC were at increased risk of CRC mortality compared with reference individuals also diagnosed with CRC [HR = 1.30 (95% CI 1.06–1.59)] and tumour stage at CRC diagnosis did not differ between groups (p = 0.27). CD patients who had 8 or more years of follow-up or who were diagnosed with primary sclerosing cholangitis (PSC) and hence were potentially eligible for CRC surveillance had an increased overall risk of CRC death [HR 1.41 (95% CI 1.18–1.69)] or CRC diagnosis [HR = 1.12 (95% CI = 0.98–1.28)]. However, in patients potentially eligible for CRC surveillance, we only found significantly increased risks in patients with CD onset <40 years, disease activity in the colon only, or with PSC (Figure 1).

Conclusion

CD patients are at increased risk of a CRC diagnosis and CRC death. Despite repeated colonoscopies during follow-up, CD patients are not diagnosed earlier (less severe tumour stage) with CRC than reference individuals. Nevertheless, CD patients with CRC have higher mortality than non-CD patients also diagnosed with CRC. CRC surveillance could likely be improved and should be focussed on CD patients <40 years at CD onset, patients with colon inflammation, and patients who have PSC.
OP16 Influence of early life factors on the development of intestinal microbiota of infants born to mothers with and without IBD
Authors: Guedelha Sabino J , Tarassishin L , Eisele C , Barré A , Dubinsky M , Stone J , Nair N , Debebe A , Hawkins K , Rendon A , Hu J , Colombel J F , Inga P , Torres J
Published: January 2020

Background

Inflammatory bowel diseases (IBD) are associated with a dysregulation of the intestinal microbiota and some of these dysbiotic taxa may be transmitted to the offspring of pregnant patients with IBD. We analysed the influence of early life events on the development of the intestinal microbiota of infants born to mothers with and without IBD.

Methods

The MECONIUM (Exploring MEChanisms Of disease traNsmission In Utero through the Microbiome) study is a prospective cohort study including pregnant women with or without IBD and their infants. Stool samples were collected during pregnancy and in babies throughout the first 2 years of life. Stool microbiota composition in the baby stool was assessed using 16S rRNA sequencing.

Results

We analysed 1037 faecal samples from 294 infants (born to 80 mothers with and 214 without IBD). The overall composition of the microbiota at 1 month was influenced by the mode of delivery (r = 0.1224, p = 0.001), feeding (breastfeeding, formula feeding or mixed; r = 0.0366, p = 0.013), and antibiotics (r = 0.0446, p = 0.004), and this was mainly driven by α-diversity (Simpson, r = 0.0529, p = 0.012), and the relative abundance of Bacteroides (r = 0.8738, p = 0.001), Bifidobacterium (r = 0.4282, p = 0.001), and Klebsiella (r = 0.6182, p = 0.001). Univariate and multivariate analysis confirmed the influence of mode of delivery in the relative abundance of Bacteroides (increased in vaginal delivery, Wilcoxon FDR p = 2.50e−07, Maaslin FDR p = 0.0016) at month 1. At month 3, mode of delivery (r = 0.0779, p = 0.001), IBD status of the mothers (r = 0.0253, p = 0.028), and pre-term birth (r = 0.0208, p = 0.045) influenced the overall composition of the microbiota, with the main drivers being Bifidobacterium (r = 0.8844, p = 0.001), Bacteroides (r = 0.8632, p = 0.001), and Klebsiella (r = 0.4374, p = 0.001). Univariate and multivariate analysis confirmed the influence of mode of delivery in the relative abundance of Bacteroides (increased in vaginal delivery, Wilcoxon FDR p = 1.23e−06, Maaslin FDR p = 0.07). None of the evaluated variables could significantly explain the variation of the overall composition of the microbiota at 1 year of life. IBD status of the mother influences the microbiota composition of 2-year-old infants; however, this association was only significant in vector fitting analysis.

Conclusion

Maternal IBD status is shaping early life microbiota in their offspring, likely due to altered microbiota in mothers with IBD. Additionally, the mode of delivery, feeding, and exposure to antibiotics are important determinants of the infant′s microbiota. These influences are lost with time, probably due to increasing exposure to several sources of microbiota and to confounding factors (e.g. diet).
OP17 Protein intakes and risk of inflammatory bowel disease in the European Prospective Investigation into Cancer and Nutrition cohort (EPIC-IBD)
Authors: Dong C , Mahamat-Saleh Y , Racine A , Jantchou P , Chan S , Hart A , Carbonnel F , Boutron-Ruault M C
Published: January 2020

Background

Diet may contribute to inflammatory bowel disease (IBD) pathogenesis. In a previous French cohort, we found an association between high protein intake and increased risk of IBD. We aimed to investigate this relationship in the EPIC-IBD (European Prospective Investigation into Cancer and Nutrition – Inflammatory Bowel Diseases) cohort.

Methods

413 593 participants from 8 European countries were included. Dietary data were collected at baseline from validated food frequency questionnaires. Mean daily intake of nutrients was assessed using the EPIC nutrient database. To reduce bias in the estimation of relative risks, calibrated dietary data were obtained from the country and sex-specific calibration models for all participants. Associations between proteins (total, animal, and vegetable) or food sources of animal proteins, and IBD risk were estimated by Cox proportional hazard models.

Results

After a mean follow-up of 16 years, 595 incident cases of IBD were identified, including 177 Crohn’s disease (CD) and 418 ulcerative colitis (UC) cases. No association was observed between total protein intake and IBD risk (adjusted HR for the fourth vs. the first quartile = 1.25; CI 95% = 0.89–1.77, P-trend = 0.33). There was a significant association between the calibrated continuous variable of animal protein intake and IBD risk (adjusted HR per 10 g/day: 1.10; 95% CI = 1.004–1.21) although no association was found for extreme quartiles (HR: 0.99; 95% CI = 0.73–1.34; P-trend = 0.91). There was no association between vegetable protein intake and IBD risk. There was an association between meat consumption and IBD risk (adjusted HR for the fourth vs.. the first quartile = 1.37; CI95% = 1.02–1.82, P-trend = 0.003) and between red meat consumption and IBD risk (adjusted HR for the fourth vs. the first quartile = 1.41; CI95% = 1.03–1.92, P-trend = 0.006). In separate analyses for CD and UC, there was an association between total meat and UC risk, and between red meat and UC risk. No association was found between food sources of animal proteins and CD risk.

Conclusion

Animal protein intake is associated with IBD risk in the EPIC-IBD cohort. Observed associations between meat consumption and IBD or UC risk, and between red meat consumption and IBD or UC risk deserve further investigation.