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Magnetic resonance imaging may predict deep remission in patients with perianal fistulizing Crohn's disease

World Journal of Gastroenterology 2017年第23期23卷 4285-4292页

作者： Lucie Thomassin Laura Armengol-Debeir Cloé Charpentier Valerie Bridoux edith koning Guillaume Savoye Céline Savoye-Collet Department of Gastroenterology Rouen University HospitalUniversity of Rouen Department of Radiology Rouen University HospitalUniversity of Rouen Department of Digestive Surgery Rouen University HospitalUniversity of Rouen

To evaluate the imaging course of Crohn’s disease (CD) patients with perianal fistulas on long-term maintenance anti-tumor necrosis factor (TNF)-α therapy and identify predictors of deep *** patients with perianal CD treated with anti-TNF-α therapy at our tertiary care center were evaluated by magnetic resonance imaging (MRI) and clinical assessment. Two MR examinations were performed: at initiation of anti-TNF-α treatment and then at least 2 years after. Clinical assessment (remission, response and non-response) was based on Present’s criteria. Rectoscopic patterns, MRI Van Assche score, and MRI fistula activity signs (T2 signal and contrast enhancement) were collected for the two MR examinations. Fistula healing was defined as the absence of T2 hyperintensity and contrast enhancement on MRI. Deep remission was defined as the association of both clinical remission, absence of anal canal ulcers and healing on MRI. Characteristics and imaging patterns of patients with and without deep remission were compared by univariate and multivariate ***-nine consecutive patients (31 females and 18 males) were included. They ranged in age from 14-70 years (mean, 33 years). MRI and clinical assessment were performed after a mean period of exposure to anti-TNF-α therapy of 40 ± 3.7 mo. Clinical remission, response and non-response were observed in 53.1%, 20.4%, and 26.5% of patients, respectively. Deep remission was observed in 32.7% of patients. Among the 26 patients in clinical remission, 10 had persisting inflammation of fistulas on MRI (T2 hyperintensity, n = 7; contrast enhancement, n = 10). Univariate analysis showed that deep remission was associated with the absence of rectal involvement and the absence of switch of anti-TNF-α treatment or surgery requirement. Multivariate analysis demonstrated that only the absence of rectal involvement (OR = 4.6; 95%CI: 1.03-20.5) was associated with deep *** remission is achieved i

关键词： Crohn’s disease Anal fistula Magnetic resonance imaging Anus disease/diagnosis Biotherapy

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Gender influence on defecographic abnormalities in patients with posterior pelvic floor disorders

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World Journal of Gastroenterology 2010年第4期16卷 462-466页

作者： Céline Savoye-Collet Guillaume Savoye edith koning Anne-Marie Leroi Jean-Nicolas Dacher Radiology Department QUANT-IF LITIS EA 4108Rouen University Hospital Charles Nicolle1 rue de GermontF76031 RouenFrance Gastroenterology Department ADEN EA 4311Rouen University Hospital Charles Nicolle1 rue de GermontF-76031 RouenFrance Physiology Department ADEN EA 4311Rouen University Hospital Charles Nicolle1 rue de GermontF-76031 RouenFrance

AIM:To compare defecographic abnormalities in symptomatic men and women and to analyze differences between men and age-and symptom-matched ***:Sixty-six men(mean age:55.4 years,range:20-81 years) who complained of constipation and/or fecal incontinence and/or pelvic pain underwent defecography after intake of a barium *** were analyzed for the diagnosis of rectocele,enterocele,intussusception and perineal *** were compared with age-and symptom-matched women(n = 198) who underwent defecography during the same ***:Normal defecography was observed in 22.7% of men vs 5.5% of women(P < 0.001).Defecography in men compared with women showed 4.5%vs 44.4%(P < 0.001) rectocele,and 10.6% vs 29.8%(P < 0.001) enterocele,*** difference was observed for the diagnosis of intussusception(57.6% vs 44.9%).Perineal descent at rest was more frequent in women(P < 0.005).CONCLUSION:For the same complaint,diagnosis of defecographic abnormalities was different in men than in women:rectocele,enterocele and perineal descent at rest were observed less frequently in men than in women.

关键词： Fecal incontinence Defecography Rectocele Hernia Pelvic floor Constipation

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A quark nova in the wake of a core-collapse supernova:a unifying model for long duration gamma-ray bursts and fast radio bursts

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Research in Astronomy and Astrophysics 2020年第2期20卷 119-186页

作者： Rachid Ouyed Denis Leahy Nico koning Department of Physics and Astronomy University of Calgary

By appealing to a quark nova(QN;the explosive transition of a neutron star to a quark star) in the wake of a core-collapse supernova(CCSN) explosion of a massive star,we develop a unified model for long duration gamma-ray bursts(LGRBs) and fast radio bursts(FRBs).The time delay(years to decades)between the SN and the QN,and the fragmented nature(i.e.,millions of chunks) of the relativistic QN ejecta are key to yielding a robust LGRB *** our model,an LGRB light curve exhibits the interaction of the fragmented QN ejecta with turbulent(i.e.,filamentary and magnetically saturated) SN ejecta which is shaped by its interaction with an underlying pulsar wind nebula(PWN).The afterglow is due to the interaction of the QN chunks,exiting the SN ejecta,with the surrounding *** model can fit BAT/XRT prompt and afterglow light curves simultaneously with their spectra,thus yielding the observed properties of LGRBs(e.g.,the Band function and the X-ray flares).We find that the peak luminositypeak photon energy relationship(i.e.,the Yonetoku law),and the isotropic energy-peak photon energy relationship(i.e.,the Amati law) are not fundamental but ***-like emission in our model results from coherent synchrotron emission(CSE) when the QN chunks interact with non-turbulent weakly magnetized PWN-SN ejecta,where conditions are prone to the Weibel *** field amplification induced by the Weibel instability in the shocked chunk frame sets the bunching length for electrons and pairs to radiate *** resulting emission frequency,luminosity and duration in our model are consistent with FRB *** find a natural unification of high-energy burst phenomena from FRBs(i.e.,those connected to CCSNe) to LGRBs including X-ray flashes(XRFs) and X-ray rich GRBs(XRR-GRBs) as well as superluminous SNe(SLSNe).We find a possible connection between ultra-high energy cosmic rays and FRBs and propose that a QN following a binary neutron star merger can yiel

关键词： stars:neutron stars:quark pulsars:general supernovae:general gamma-ray burst:general fast radio burst:general

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Hints of a second explosion(a quark nova) in Cassiopeia A supernova

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Research in Astronomy and Astrophysics 2015年第4期15卷 483-500页

作者： Rachid Ouyed Denis Leahy Nico koning Department of Physics and Astronomy University of Calgary

We show that the explosive transition of the neutron star （NS） to a quark star （QS）（a Quark Nova） in Cassiopeia A （Cas A） a few days following the supernova （SN） proper can account for several of the puzzling kinematic and nucleosynthetic features that are observed. The observed decoupling between Fe and 44Ti and the lack of Fe emission within 44Ti regions is expected in the QN model owing to the spallation of the inner SN ejecta by relativistic QN neutrons. Our model predicts the 44Ti to be more prominent to the NW of the central compact object （CCO） than in the SE and little of it along the NE-SW jets, in agreement with NuStar observations. Other intriguing features of Cas A are addressed, such as the lack of a pulsar wind nebula and the reported few percent drop in the CCO temperature over a period of 10 yr.

关键词： ISM: individual object (Cassiopeia A) -- ISM: supemova remnants --stars: neutron

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SN 2009ip and SN 2010mc as dual-shock Quark-Novae

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Research in Astronomy and Astrophysics 2013年第12期13卷 1463-1470页

作者： Rachid Ouyed Nico koning Denis Leahy Department of Physics and Astronomy University of Calgary 2500 University Drive NW

In recent years a number of double-humped supernovae （SNe） have been discovered. This is a feature predicted by the dual-shock Quark-Nova （QN） model where an SN explosion is followed （a few days to a few weeks later） by a QN explo- sion. SN 2009ip and SN 2010mc are the best observed examples of double-humped SNe. Here, we show that the dual-shock QN model naturally explains their light curves including the late time emission, which we attribute to the interaction between the mixed SN and QN ejecta and the surrounding circumstellar matter. Our model applies to any star （O-stars, luminous blue variables, Wolf-Rayet stars, etc.） provided that the mass involved in the SN explosion is ~ 20 Mo which provides good conditions for forming a QN.

关键词： circumstellar matter -- stars: evolution -- stars: winds outflows --supernovae: general -- supernovae: individual (SN 2009ip SN 2010mc)

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Quark nova model for fast radio bursts

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Research in Astronomy and Astrophysics 2016年第5期16卷 87-98页

作者： Zachary Shand Amir Ouyed Nico koning Rachid Ouyed Department of Physics and Astronomy University of Calgary

Fast radio bursts （FRBs） are puzzling, millisecond, energetic radio transients with no discernible source; observations show no counterparts in other frequency bands. The birth of a quark star from a parent neutron star experiencing a quark nova - previously thought undetectable when born in isolation - provides a natural explanation for the emission characteristics of FRBs. The generation of unstable r-process elements in the quark nova ejecta provides millisecond exponential injection of electrons into the surrounding strong magnetic field at the parent neutron star＇s light cylinder via β-decay. This radio synchrotron emission has a total duration of hundreds of milliseconds and matches the observed spectrum while reducing the inferred dispersion measure by approximately 200 cm-3 pc. The model allows indirect measurement of neutron star magnetic fields and periods in addition to providing astronomical measurements of β-decay chains of unstable neutron rich nuclei. Using this model, we can calculate expected FRB average energies （- 1041 erg） and spectral shapes, and provide a theoretical framework for determining distances.

关键词： stars: neutron -- nuclear reactions nucleosynthesis abundances -- radiation mechanisms:general -- radio continuum: general

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Bayesian model averaging(BMA)for nuclear data evaluation

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Nuclear Science and Techniques 2024年第11期35卷 193-218页

作者： E.Alhassan D.Rochman G.Schnabel A.J.koning SCK CEN(Belgian Nuclear Research Centre) Boeretang 2002400 MolBelgium Laboratory for Reactor Physics and Thermal‑Hydraulics Paul Scherrer Institute5232 VilligenSwitzerland Nuclear Data Section International Atomic Energy Agency(IAEA)ViennaAustria Division of Applied Nuclear Physics Department of Physics and AstronomyUppsala UniversityUppsalaSweden

To ensure agreement between theoretical calculations and experimental data,parameters to selected nuclear physics models are perturbed and fine-tuned in nuclear data *** approach assumes that the chosen set of models accurately represents the‘true’distribution of considered ***,the models are chosen globally,indicating their applicability across the entire energy range of ***,this approach overlooks uncertainties inherent in the models *** this work,we propose that instead of selecting globally a winning model set and proceeding with it as if it was the‘true’model set,we,instead,take a weighted average over multiple models within a Bayesian model averaging(BMA)framework,each weighted by its posterior *** method involves executing a set of TALYS calculations by randomly varying multiple nuclear physics models and their parameters to yield a vector of calculated ***,computed likelihood function values at each incident energy point were then combined with the prior distributions to obtain updated posterior distributions for selected cross sections and the elastic angular *** the cross sections and elastic angular distributions were updated locally on a per-energy-point basis,the approach typically results in discontinuities or“kinks”in the cross section curves,and these were addressed using spline *** proposed BMA method was applied to the evaluation of proton-induced reactions on ^(58)Ni between 1 and 100 *** results demonstrated a favorable comparison with experimental data as well as with the TENDL-2023 evaluation.

关键词： Bayesian model averaging(BMA) Nuclear data Nuclear reaction models Model parameters TALYS code system Covariances

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Offering Adequate Pedagogical Progression via Mobile Equipments——Experiment of a French Engineering School

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开放教育研究 2006年第1期12卷 59-62页

作者： Jean-Luc koning Grenoble National Institute of Technology France

Students may enter our 5-year engineering school in France at two levels; first and third year. However, due to their quite different backgrounds (this is especially true for third year students) , we need to provide newcomers with a 6-week training period during which they follow classes in the fields where they particularly feel weak. Unfortunately, depending on the student' s background, this is not always possible to bring him/her to the expected level. Another aspect one needs to mention is that these students may not have the same weaknesses in a given field. However, for economical reasons, those classes follow a uniform program as it is not feasible to provide a customised progression. In this paper we discuss how to redesign a mathematics course so as to offer tailored exercise sequencing. Groups of 20 students could then draw their exercises from an intranet database according to their previously completed work, try to solve it by themselves, request additional hints and even ask for some direct help from the teacher. Such a database is currently under development. If it turns out several students stumble against the same difficulty the teacher could show the whole class room how to solve it using the digital projector. This project goes one step further than our initial mobile education project (2003 - 2004 ). Until recently, we had used the equipment in a unique direction, from the instructor toward the students. Here, in this new project we are focusing on the whole loop in order to offer a more adequate (personalized) pedagogical progression ; from the student to the teacher (when the tablet PCs are monitored by the teacher) , and back toward the students (when a direct help is provided by the teacher).

关键词：法国移动学习设备工程院校开放教育教学方法

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Quark-Novae Ia in the Hubble diagram: implications for dark energy

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Research in Astronomy and Astrophysics 2014年第5期14卷 497-519页

作者： Rachid Ouyed Nico koning Denis Leahy Jan E.Staff Daniel T.Cassidy Department of Physics and Astronomy University of Calgary 2500 University Drive NWCalgary Alberta T2N 1N4 Canada Department of Physics and Astronomy Macquarie University NSW 2109 Australia Department of Engineering Physics McMaster University Hamilton Ontario L8S 4L7 Canada

The accelerated expansion of the Universe was proposed through the use of Type-Ia supernovae （SNe） as standard candles. The standardization depends on an empirical correlation between the stretch/color and peak luminosity of the light curves. The use of Type-Ia SNe as standard candles rests on the assumption that their properties （and this correlation） do not vary with redshift. We consider the possibility that the majority of Type-Ia SNe are in fact caused by a Quark-Nova detonation in a tight neutron-star-CO-white-dwarf binary system, which forms a Quark-Nova Ia （QN-Ia）. The spin-down energy injected by the Quark-Nova remnant （the quark star） contributes to the post-peak light curve and neatly explains the observed correlation between peak luminosity and light curve shape. We demonstrate that the parameters describing QN-Ia are NOT constant in redshift. Simulated QN-Ia light curves provide a test of the stretch/color correlation by comparing the true distance modulus with that determined using SN light curve fitters. We determine a correction between the true and fitted distance moduli, which when applied to Type-Ia SNe in the Hubble diagram recovers the ΩM = 1 cosmology. We conclude that Type-Ia SNe observations do not necessitate the need for an accelerating expansion of the Universe （if the observed SNe Ia are dominated by QNe Ia） and by association the need for dark energy.

关键词： dark energy -- cosmology observations -- supernovae general

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Scalable Jet-Based Fabrication of PEI-Hydrogel Particles for CO_(2) Capture

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Energy & Environmental Materials 2024年第6期7卷 351-358页

作者： Jieke Jiang Eline van Daatselaar Hylke Wijnja Tessa de koning Gans Michel Schellevis Cornelis H.Venner Derk W.F.Brilman Claas Willem Visser Engineering Fluid Dynamics Group Department of Thermal and Fluid EngineeringFaculty of Engineering TechnologyUniversity of Twente7500AEEnschedeThe Netherlands Sustainable Process Technology Faculty of Science and TechnologyUniversity of Twente7500AEEnschedeThe Netherlands

The capture,regeneration,and conversion of CO_(2) from ambient air and flue gas streams are critical aspects of mitigating global *** sorbents for CO_(2) absorption are very promising as they have high mass transfer areas without energy input and reduce emissions and minimize corrosion as compared to liquid ***,precisely tunable solid CO_(2) sorbents are difficult to ***,we demonstrate the high-throughput production of hydrogel-based CO_(2)-absorbing particles via liquid *** wrapping a liquid jet consisting of an aqueous solution of cross-linkable branched polyethylenimine(PEI)with a layer of suspension containing hydrophobic silica nanoparticles,monodisperse droplets with a silica nanoparticle coating layer was formed in the air.A stable Pickering emulsion containing PEI droplets was obtained after these ejected droplets were collected in a heated oil *** droplets turn into mm-sized particles after thermal curing in the *** diameter,PEI content,and silica content of the particles were systematically varied,and their CO_(2) absorption was measured as a function of *** regeneration of the particles enabled cyclic testing,revealing a CO_(2) absorption capacity of 6.5±0.5 mol kg^(−1)solid PEI in pure CO_(2) environments and 0.7±0.3 mol kg^(−1)solid PEI for direct air *** thousands of particles were produced per second at a rate of around 0.5 kg per hour,with a single *** process can be further scaled by *** complete toolbox for the design,fabrication,testing,and regeneration of functional hydrogel particles provides a powerful route toward novel solid sorbents for regenerative CO_(2) capture.

关键词： CO_(2) capture droplet hydrogel liquid jet particle steam regeneration

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