999 results on '"Dollfus, P."'
Search Results
2. Multi-view graph-based interview representation to improve depression level estimation
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Agarwal, Navneet, Dias, Gaël, and Dollfus, Sonia
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- 2024
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3. Multi-view graph-based interview representation to improve depression level estimation
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Navneet Agarwal, Gaël Dias, and Sonia Dollfus
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Graph-based interview transcript representation ,Multi-view architectures ,Similarity graphs ,Keyword correlation graphs ,Insight generation ,Automatic depression level estimation ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Computer software ,QA76.75-76.765 - Abstract
Abstract Depression is a serious mental illness that affects millions worldwide and consequently has attracted considerable research interest in recent years. Within the field of automated depression estimation, most researchers focus on neural network architectures while ignoring other research directions. Within this paper, we explore an alternate approach and study the impact of input representations on the learning ability of the models. In particular, we work with graph-based representations to highlight different aspects of input transcripts, both at the interview and corpus levels. We use sentence similarity graphs and keyword correlation graphs to exemplify the advantages of graphical representations over sequential models for binary classification problems within depression estimation. Additionally, we design multi-view architectures that split interview transcripts into question and answer views in order to take into account dialogue structure. Our experiments show the benefits of multi-view based graphical input encodings over sequential models and provide new state-of-the-art results for binary classification on the gold standard DAIC-WOZ dataset. Further analysis establishes our method as a means for generating meaningful insights and visual summaries of interview transcripts that can be used by medical professionals.
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- 2024
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4. Response to comment on: Could internal limiting membrane peeling before Voretigen Neparvovec-ryzl subretinal injection prevent focal chorioretinal atrophy?
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Lea Dormegny, Fouzia Studer, Arnaud Sauer, Laurent Ballonzoli, Claude Speeg-Schatz, Tristan Bourcier, Helene Dollfus, and David Gaucher
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Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Published
- 2024
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5. Current management of primary mitochondrial disorders in EU countries: the European Reference Networks survey
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Mancuso, Michelangelo, Lopriore, Piervito, Lamperti, Costanza, Klopstock, Thomas, Rahman, Shamima, Licchetta, Laura, Kornblum, Cornelia, Wortmann, Saskia B., Dollfus, Hélène, Papadopoulou, Maria T., Arzimanoglou, Alexis, Scarpa, Maurizio, Graessner, Holm, and Evangelista, Teresinha
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- 2024
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6. Minimum thermal conductance of twisted-layer graphite nanofibers
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Tran, Van-Truong, Vu, Thanh-Tra, Dollfus, Philippe, Saint-Martin, Jérôme, and Pala, Marco
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We study the thermal transport properties of twisted-layer graphite nanofibers. We show that in the presence of a twisted layer, the phonon thermal conductance of a graphite nanofiber varies remarkably with the twisted angle and can reach minimum values either at two critical angles $\theta_1$ and $\theta_2$ that conform to the rule $\theta_1$ + $\theta_1$ = $180^0$ or exactly at the angle $\theta$ = $90^0$. A reduction of roughly 50% of the phonon thermal conductance can be achieved in some structures. We unveil that the twisting effect mainly influences the optical modes, leaving almost unaltered the acoustic ones. The effect is also visible in the higher and more numerous van Hove singularities of the phonon density of states. We also point out that the behavior of the thermal conductance with the twisted angle is associated with and dominated by the alteration in the overlap area between the twisted and non-twisted layers. The finite-size effect is demonstrated to play an essential role in defining the critical angles at the local minimums, where these angles are dependent on the size of the investigated nanofibers, in particular on the proportion between the widths of zigzag and armchair edges., Comment: 19 pages,7 figures
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- 2022
7. Immunovirological status in people with perinatal and adult-acquired HIV-1 infection: a multi-cohort analysis from FranceResearch in context
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Rémonie Seng, Pierre Frange, Albert Faye, Catherine Dollfus, Jérôme le Chenadec, Faroudy Boufassa, Asma Essat, Tessa Goetghebuer, Elisa Arezes, Véronique Avettand-Fènoël, Jean-Joël Bigna, Stéphane Blanche, Cécile Goujard, Laurence Meyer, Josiane Warszawski, Jean-Paul Viard, H. Aumaitre, E. Froguel, F. Caby, S. Dellion, L. Gerard, F. Lucht, C. Chirouze, M. Dupon, Jl Schmit, C. Goujard, T. Allegre, B. Cazenave, G. Hittinger, P. De Truchis, J. Cailhol, C. Duvivier, A. Canestri, O. Bouchaud, M. Karmochkine, D. Salmon-Ceron, D. Zucman, E. Mortier, R. Tubiana, P.M. Girard, C. Pintado, A. Cabie, V. Rabier, P. Morlat, D. Neau, C. Genet, D. Makhloufi, S Bregigeon Ronot, J. Ghosn, V. Reliquet, P. Perré, Jl Pellegrin, C. Arvieux, C. Cheneau, L. Bernard, P. Delobel, R. Verdon, C. Jacomet, L. Piroth, F. Ajana, S. Bevilacqua, Y. Debab, A.L. Lecapitaine, L. Cotte, S. Mokhtari, P. Mercie, P. Poubeau, V. Garrait, Ma Khuong, G. Beck-Wirth, L. Blum, S. Blanche, F. Boccara, T. Prazuck, C. Barbuat, J.P. Viard, S. Stegmann-Planchard, B. Martha, J.M. Treluyer, E. Dore, C. Gaud, M. Niault, E. Fernandes, H. Hitoto, A. Compagnucci, N. Elenga, A. Faye, C. Dollfus, A. Chace, M. Levine, S.A. Martha, C. Floch-Tudal, K. Kebaïli, N. Entz-Werle, J. Tricoire, F. Mazingue, P. Bolot, P. Brazille, T. Goetghebuer, A.F. Gennotte, D. Van Der Linden, V. Schmitz, M. Moutschen, C. Crenn-Hebert, F. Habibi, A. Coursol, E. Guesdon, P.F. Ceccaldi, M. Dehlinger – Paul, E. Pannier, V. Marcou, C. Elleau, M. Achkar, M.O. Vareil, S. Couderc, C. Routier, M.A. Bouldouyre, L. Selleret, A. Chabrol, C. Bellahcene, C. Pluchart, A. Yangui, D. Vignes, A. Alissa, A. Johnson, E. Lachassinne, A. Benbara, L. Karaoui, A. Bongain, B. Yakeu, J.L. Schmit, L. Cravello, C. Hubert, P. Faucher, D. Pinquier, C. Borie, D. Rocchi, C. Brunet-Cartier, C. Briandet, J. Brouard, A. Chalvon-Demersay, M. Rajguru, K. Billiemaz, A. Fresard, A. Moulin, P. Fialaire, L. Mesnard, E. Werner, E. Vintejoux, J. Marian, S. Ranaivojaona, F. Bissuel, M. Abdelhadi, Y. Hammou, C. Genet-Villeger, Y. Hatchuel, G. Bachelard, M. Medus, J. Dendale – Nguyen, T.S. Guimard, A. Martha, M. Rouha, P. Perfezou, L. De Saint Martin, S. Jaffuel, R. Buzele, M. Gousseff, C. Cudeville, V. Vitrat, C. Michau, G. Palenzuela, M. Driessen, B. Heller-Roussin, J.M. Labaune, B. Muanza, J. Massardier, M. Partisani, I. Hau, C. Runel-Belliard, C. Brehin, K. Kebaili, M. Lalande, M. Lagree, K. Lacombe, J.-M. Molina, J. Reynes, O. Robineau, F. Raffi, A. Becker, L. Weiss, T. Allègre, G. Pialoux, F. Souala, A. Rami, C. Katlama, A. Cabié, J.-P. Viard, F. Bastides, C. Michel, D. Salmon, J-D Le Lièvre, A. Sotto, E. Rouveix, A. Naqvi, S. Brégigeon, R. Rodet, A. Simon-Coutelier, J.-L. Esnault, R. Buzelé, A. Stein, C. Godin-Colet, G. Pichancourt, P. Caraux-Paz, M Mohseni Zadeh, L. Gérard, C. Lascaux-Cametz, L. Bodard, J.-L. Pellegrin, N. Ettahar, A. Uludag, E. Rosenthal, F. Prevoteau du Clary, S. Jaureguiberry, P. Philibert, A.-L. Lecapitaine, E. Chakvetadze, H. Champagne, V. Daneluzzi, J. Goupil de Bouillé, A. Leprêtre, I. Lamaury, I. Darasteanu, B. Abraham, D. Garipuy, J.-L. Berger, J.-L. Schmit, K. Diallo, F. Gourdon, O. Vaillant, V. Gaborieau, J. Doll, D. Quinsat, L. Geffray, J.-J. Girard, D. Houlbert, V. Perronne, E. Klement, O. Antioniotti, C. Rouzioux, V. Avettand-Fenoel, O. Lortholary, S. Boucly, A. Maignan, R. Thiebaut, L. Meyer, F. Boufassa, M.A. Charles, R. Dray-Spira, C. Legeai, V. Amon, N. Benammar, R. Seng, L. Slama, P. Bonnard, C. Chakvetadze, T. L’Yavanc, J. Capeau, C. Vigouroux, S. Fellahi, J.P. Bastard, E. Oksenhendler, J.F. Bourge, V. Bajzik, D. Sereni, C. Lascoux-Combe, O. Taulera, L.V. Dien, J. Delgado, J.M. Molina, T. Saint-Marc, S. Ferret, J. Pavie, J.F. Bergmann, M. Parrinello, BLefebvre, C. Boudraa, B. Diallo, C. Lupin, S. Herson, A. Simon, N. Edeb, L. Guillevin, T. Tahi, M.P. Pietri, D. Tisne-Dessus, C. Jalbert, P. Yeni, S. Matheron, G. Pahlavan, B. Phung, N. El-Alami Talbi, Z. Ramani, G. Catalano, C. Godard, F. Boue, V. Chambrin, D. Bornarel, H. Schoen, R. Carlier, B. Fantin, C. Poder, R. Dhote, M. Bentata, P. Honore, Xuan Tuyet, J.F. Delfraissy, F. Chaix, M.T. Rannou, Y. Levy, A. Sobel, C. Dumont, S. Abel, S. Pierre-François, V. Beaujolais, I. Poizot-Martin, O. Zaegel-Faucher, C. Debreux, J. Moreau, E. Van Der Gheynst, M.C. Thiebaut-Drobacheff, A. Foltzer, B. Hoen, J.F. Faucher, H. Gil, J.M. Ragnaud, I. Raymond, I. Louis, M. Hessamfar, V. Baillat, C Merle De Boever, C. Tramoni, A. Soufflet, P. Guadagnin, P. Choutet, O. Mounoury, D. Brosseau, H. Hue, T. May, S. Wassoumbou, M. Stenzel, M.P. Bouillon, Y. Yazdanpanah, T. Huleux, E. Aissi, S. Pavel, D. Rey, P. Fischer, G. Blaison, M. Martinot, A. Pachart, F. Jeanblanc, J.L. Touraine, C. Trepo, P. Miailhes, K. Kouadjo, V. Thoirain, C. Brochier, P. Perre, S. Leautez, J.L. Esnault, and I. Suaud
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Perinatal HIV infection ,Cohort ,Viral failure ,Immunological outcome ,Epidemiology ,Public aspects of medicine ,RA1-1270 - Abstract
Summary: Background: No study has compared the virological and immunological status of young people with perinatally-acquired HIV infection (P-HIV) with that of people with HIV adulthood (A-HIV) having a similar duration of infection. Methods: 5 French cohorts of P-HIV and A-HIV patients with a known date of HIV-infection and receiving antiretroviral treatment (ART), were used to compare the following proportions of: virological failure (VF) defined as plasma HIV RNA ≥ 50 copies/mL, CD4 cell percentages and CD4:CD8 ratios, at the time of the most recent visit since 2012. The analysis was stratified on time since infection, and multivariate models were adjusted for demographics and treatment history. Findings: 310 P-HIV were compared to 1515 A-HIV (median current ages 20.9 [IQR:14.4–25.5] and 45.9 [IQR:37.9–53.5] respectively). VF at the time of the most recent evaluation was significantly higher among P-HIV (22.6%, 69/306) than A-HIV (3.3%, 50/1514); p ≤ 0.0001. The risk of VF was particularly high among the youngest children (2–5 years), adolescents (13–17 years) and young adults (18–24 years), compared to A-HIV with a similar duration of infection: adjusted Odds-Ratio (aOR) 7.0 [95% CI: 1.7; 30.0], 11.4 [4.2; 31.2] and 3.3 [1.0; 10.8] respectively. The level of CD4 cell percentages did not differ between P-HIV and A-HIV. P-HIV aged 6–12 and 13–17 were more likely than A-HIV to have a CD4:CD8 ratio ≥ 1: 84.1% vs. 58.8% (aOR = 3.5 [1.5; 8.3]), and 60.9% vs. 54.7% (aOR = 1.9 [0.9; 4.2]) respectively. Interpretation: P-HIV were at a higher risk of VF than A-HIV with a similar duration of infection, even after adjusting for treatment history, whereas they were not at a higher risk of immunological impairment. Exposure to viral replication among young patients living with HIV since birth or a very early age, probably because of lower adherence, could have an impact on health, raising major concerns about the selection of resistance mutations and the risk of HIV transmission. Funding: Inserm - ANRS MIE.
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- 2024
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8. Sulcal pits of the superior temporal sulcus in schizophrenia patients with auditory verbal hallucinations
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Baptiste Lerosier, Gregory Simon, Sylvain Takerkart, Guillaume Auzias, and Sonia Dollfus
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schizophrenia ,auditory verbal hallucination ,structural mri ,superior temporal sulcus ,sulcal pits ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Auditory verbal hallucinations (AVHs) are among the most common and disabling symptoms of schizophrenia. They involve the superior temporal sulcus (STS), which is associated with language processing; specific STS patterns may reflect vulnerability to auditory hallucinations in schizophrenia. STS sulcal pits are the deepest points of the folds in this region and were investigated here as an anatomical landmark of AVHs. This study included 53 patients diagnosed with schizophrenia and past or present AVHs, as well as 100 healthy control volunteers. All participants underwent a 3-T magnetic resonance imaging T1 brain scan, and sulcal pit differences were compared between the two groups. Compared with controls, patients with AVHs had a significantly different distributions for the number of sulcal pits in the left STS, indicating a less complex morphological pattern. The association of STS sulcal morphology with AVH suggests an early neurodevelopmental process in the pathophysiology of schizophrenia with AVHs.
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- 2024
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9. Ab-initio simulation of dissipative transport in tunnel devices based on heterostructures of 2D materials
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M’foukh, Adel, Saint-Martin, Jérôme, Dollfus, Philippe, and Pala, Marco
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- 2023
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10. Quality of life improvements following one year of setmelanotide in children and adult patients with Bardet–Biedl syndrome: phase 3 trial results
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Forsythe, Elizabeth, Haws, Robert M., Argente, Jesús, Beales, Philip, Martos-Moreno, Gabriel Á., Dollfus, Hélène, Chirila, Costel, Gnanasakthy, Ari, Buckley, Brieana C., Mallya, Usha G., Clément, Karine, and Haqq, Andrea M.
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- 2023
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11. Comparative Natural History of Visual Function From Patients With Biallelic Variants in BBS1 and BBS10
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Pechhacker, Monika K Grudzinska, Jacobson, Samuel G, Drack, Arlene V, Di Scipio, Matteo, Strubbe, Ine, Pfeifer, Wanda, Duncan, Jacque L, Dollfus, Helene, Goetz, Nathalie, Muller, Jean, Vincent, Andrea L, Aleman, Tomas S, Tumber, Anupreet, Van Cauwenbergh, Caroline, De Baere, Elfride, Bedoukian, Emma, Leroy, Bart P, Maynes, Jason T, Munier, Francis L, Tavares, Erika, Saleh, Eman, Vincent, Ajoy, and Heon, Elise
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Rare Diseases ,Neurosciences ,Eye Disease and Disorders of Vision ,Clinical Research ,Eye ,Adolescent ,Adult ,Bardet-Biedl Syndrome ,Chaperonins ,Child ,Child ,Preschool ,Electroretinography ,Female ,Humans ,Male ,Microtubule-Associated Proteins ,Middle Aged ,Mutation ,Missense ,Optical Imaging ,Refraction ,Ocular ,Retina ,Retinal Dystrophies ,Retrospective Studies ,Tomography ,Optical Coherence ,Visual Acuity ,Visual Field Tests ,Visual Fields ,blindness ,Bardet Biedl syndrome ,retinal degeneration ,genetics ,natural history ,end points ,Biological Sciences ,Medical and Health Sciences ,Ophthalmology & Optometry - Abstract
PurposeThe purpose of this study was to compare the natural history of visual function change in cohorts of patients affected with retinal degeneration due to biallelic variants in Bardet-Biedl syndrome genes: BBS1 and BBS10.MethodsPatients were recruited from nine academic centers from six countries (Belgium, Canada, France, New Zealand, Switzerland, and the United States). Inclusion criteria were: (1) female or male patients with a clinical diagnosis of retinal dystrophy, (2) biallelic disease-causing variants in BBS1 or BBS10, and (3) measures of visual function for at least one visit. Retrospective data collected included genotypes, age, onset of symptoms, and best corrected visual acuity (VA). When possible, data on refractive error, fundus images and autofluorescence (FAF), optical coherence tomography (OCT), Goldmann kinetic perimetry (VF), electroretinography (ERG), and the systemic phenotype were collected.ResultsSixty-seven individuals had variants in BBS1 (n = 38; 20 female patients and 18 male patients); or BBS10 (n = 29; 14 female patients and 15 male patients). Missense variants were the most common type of variants for patients with BBS1, whereas frameshift variants were most common for BBS10. When ERGs were recordable, rod-cone dystrophy (RCD) was observed in 82% (23/28) of patients with BBS1 and 73% (8/11) of patients with BBS10; cone-rod dystrophy (CORD) was seen in 18% of patients with BBS1 only, and cone dystrophy (COD) was only seen in 3 patients with BBS10 (27%). ERGs were nondetectable earlier in patients with BBS10 than in patients with BBS1. Similarly, VA and VF declined more rapidly in patients with BBS10 compared to patients with BBS1.ConclusionsRetinal degeneration appears earlier and is more severe in BBS10 cases as compared to those with BBS1 variants. The course of change of visual function appears to relate to genetic subtypes of BBS.
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- 2021
12. Study of phonon transport across several Si/Ge interfaces using full-band phonon Monte Carlo simulation
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Le, N. D., Davier, B., Izitounene, N., Dollfus, P., and Saint-Martin, J.
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Physics - Applied Physics ,Condensed Matter - Other Condensed Matter - Abstract
A Full Band Monte Carlo simulator has been developed to consider phonon transmission across interfaces that are perpendicular to the heat flux. This solver of the Boltzmann transport equation which does not require any assumption on the shape the phonon distribution can naturally consider all phonon transport regimes from the diffusive to the fully ballistic regime. Hence, this simulator is used to study single and double Si/Ge heterostructures from the micrometer scale down to the nanometer scale i.e. in all phonon transport regime from ballistic to fully diffusive. A methodology to estimate the thermal conductivities and the thermal interfaces is presented.
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- 2021
13. Functional Characterization of Splice Variants in the Diagnosis of Albinism
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Modibo Diallo, Cécile Courdier, Elina Mercier, Angèle Sequeira, Alicia Defay-Stinat, Claudio Plaisant, Shahram Mesdaghi, Daniel Rigden, Sophie Javerzat, Eulalie Lasseaux, Laetitia Bourgeade, Séverine Audebert-Bellanger, Hélène Dollfus, Smail Hadj-Rabia, Fanny Morice-Picard, Manon Philibert, Mohamed Kole Sidibé, Vasily Smirnov, Ousmane Sylla, Vincent Michaud, and Benoit Arveiler
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albinism ,splice variants ,exon skipping ,pseudoexon ,RT-PCR ,minigene assay ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Albinism is a genetically heterogeneous disease in which 21 genes are known so far. Its inheritance mode is autosomal recessive except for one X-linked form. The molecular analysis of exonic sequences of these genes allows for about a 70% diagnostic rate. About half (15%) of the unsolved cases are heterozygous for one pathogenic or probably pathogenic variant. Assuming that the missing variant may be located in non-coding regions, we performed sequencing for 122 such heterozygous patients of either the whole genome (27 patients) or our NGS panel (95 patients) that includes, in addition to all exons of the 21 genes, the introns and flanking sequences of five genes, TYR, OCA2, SLC45A2, GPR143 and HPS1. Rare variants (MAF < 0.01) in trans to the first variant were tested by RT-PCR and/or minigene assay. Of the 14 variants tested, nine caused either exon skipping or the inclusion of a pseudoexon, allowing for the diagnosis of 11 patients. This represents 9.8% (12/122) supplementary diagnosis for formerly unsolved patients and 75% (12/16) of those in whom the candidate variant was in trans to the first variant. Of note, one missense variant was demonstrated to cause skipping of the exon in which it is located, thus shedding new light on its pathogenic mechanism. Searching for non-coding variants and testing them for an effect on RNA splicing is warranted in order to increase the diagnostic rate.
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- 2024
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14. Effects of Adapted Physical Activity on White Matter Integrity in Patients with Schizophrenia
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Elise Leroux, Laura Masson, Maxime Tréhout, and Sonia Dollfus
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schizophrenia ,adapted physical activity ,TBSS ,white matter ,MRI ,negative symptoms ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Schizophrenia is associated with changes in white matter (WM) integrity and with reduced life expectancy, in part because of the cardiometabolic side effects of antipsychotics. Physical activity (PA) has emerged as a candidate lifestyle intervention that is safe and effective. The study aimed to assess how an adapted PA program delivered remotely by web (e-APA) improved WM integrity in patients with schizophrenia (SZPs) and healthy controls (HCs) and to evaluate associations among WM integrity, cardiorespiratory fitness, and symptom severity. This longitudinal study was conducted over 16 weeks with 31 participants (18 SZPs and 13 HCs). Diffusion tensor imaging and tract-based spatial statistics were employed to assess WM integrity. Cardiorespiratory fitness was measured by maximal oxygen uptake (VO2max), and assessments for clinical symptoms included the Positive and Negative Syndrome Scale, Self-evaluation of Negative Symptoms and the Brief Negative Syndrome Scale (BNSS). Only the SZPs had significantly increased WM integrity after the e-APA program, with increased fractional anisotropy and decreased radial diffusivity in fasciculi involved in motor functions and language process. Furthermore, decreased negative symptoms assessed with BNSS were associated with greater WM integrity following the program. These findings suggest that e-APA may improve WM integrity abnormalities and support e-APA as a promising therapeutic strategy.
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- 2024
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15. Agenda-Setting for COVID-19: A Study of Large-Scale Economic News Coverage Using Natural Language Processing
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Lu, Guang, Businger, Martin, Dollfus, Christian, Wozniak, Thomas, Fleck, Matthes, Heroth, Timo, Lock, Irina, and Lipenkova, Janna
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- 2023
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16. Could internal limiting membrane peeling before Voretigen neparvovec-ryzl subretinal injection prevent focal chorioretinal atrophy?
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Lea Dormegny, Fouzia Studer, Arnaud Sauer, Laurent Ballonzoli, Claude Speeg-Schatz, Tristan Bourcier, Helene Dollfus, and David Gaucher
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Leber congenital amaurosis ,RPE65-mediated retinal dystrophy ,Luxturna ,Gene therapy ,Retinitis pigmentosa ,Perifoveal chorioretinal atrophy ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Purpose: To report the effect of internal limiting membrane (ILM) peeling prior to Voretigen Neparvovec-ryzl (VN) subretinal injection on focal chorioretinal atrophy development in patients presenting with RPE65-mediated Leber congenital amaurosis (LCA). Design: Retrospective case series. Methods: Three patients who underwent bilateral subretinal VN injection for RPE65-mediated LCA were followed up for 18–24 months. ILM peeling was performed unilaterally in patients 1 and 2 and bilaterally in patient 3. Chorioretinal atrophy was identified on fundus biomicroscopy, non-mydriatic retinography and/or ultrawide field fundus imaging. Best corrected visual acuity (BCVA), spectral-domain optical coherence tomography (SD-OCT), visual fields, full-field stimulus threshold (FST) and visual functioning questionnaire score (NEI-VFQ-25) were reported. Outcome measures were changes in BCVA, visual fields, FST, NEI-VFQ-25, and chorioretinal atrophy location. Results: Chorioretinal atrophy at the injection site exclusively developed in eyes which did not undergo prior ILM peeling. In patient 3, bilateral pre-operative nummular chorioretinal alterations progressed toward epithelial atrophic patches in the mid and extreme retinal periphery 18 months after VN injection. BCVA and visual fields improved bilaterally. NEI_VFQ 25 remained stable in patient 1 and improved in patient 2 and 3. FST test improved bilaterally in patient 3. Conclusions: ILM peeling prior to VN injection seems to be a smoother and safer technique to administer VN treatment and may prevent secondary focal atrophy development at the injection site. However, another type of more extended chorioretinal atrophy might exist and could be related to LCA evolution or to incompletely understood adverse effect of VN product.
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- 2024
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17. A cold-source paradigm for steep-slope transistors based on van der Waals heterojunctions
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Logoteta, Demetrio, Cao, Jiang, Pala, Marco, Dollfus, Philippe, Lee, Youseung, and Iannaccone, Giuseppe
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
The availability of transistors capable of operating at low supply voltage is essential to improve the key performance metric of computing circuits, i.e., the number of operations per unit energy. In this paper, we propose a new device concept for energy-efficient, steep-slope transistors based on heterojunctions of 2D materials. We show that by injecting electrons from an isolated and weakly dispersive band into a strongly dispersive one, subthermionic subthreshold swings can be obtained, as a result of a cold-source effect and of a reduced thermalization of carriers. This mechanism is implemented by integrating in a MOSFET architecture two different monolayer materials coupled through a van der Waals heterojunction, combining the subthermionic behavior of tunnel field-effect transistors (FETs) with the robustness of a MOSFET architecture against performance-degrading factors, such as traps, band tails and roughness. A further advantage with respect to tunnel FETs is that only an n-type or p-type doping is required to fabricate the device. In order to demonstrate the device concept and to discuss the underlying physics and the design options, we study through abinitio and full-quantum transport simulations a possible implementation that exploits two recently reported 2D materials., Comment: Accepted for publication in Physical Review Research
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- 2020
18. Revisiting thermal conductivity and interface conductance at the nanoscale
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Davier, B., Dollfus, P., Volz, S., Shiomi, J., and Saint-Martin, J.
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
A semi-analytical model for studying thermal transport at the nanoscale, able to accurately describe both the effect of out of equilibrium transport and the thermal transfer at interfaces, is presented. Our approach is based on the definition of pseudo local temperatures distinguishing the phonon populations according to the direction of their velocity. This formalism leads to a complete set of equations capturing the heat transfer in nanostructures even in the case of hetero-structures. This model only requires introducing a new intrinsic thermal parameter called ballistic thermal conductance and a geometric one called the effective thermal conductivity. Finally, this model is able to reproduce accurately advanced numerical results of Monte Carlo simulation for phonons in all phonon transport regime: diffusive (as the Fourier heat transport regime is included), ballistic, and intermediate ones even if thermal interface are involved. This formalism should provide new insights in the interpretation of experimental measurements.
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- 2020
19. Electron transport properties of graphene nanoribbons with Gaussian deformation
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Tran, Van-Truong, Saint-Martin, Jérôme, and Dollfus, Philippe
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Gaussian deformation in graphene structures exhibits an interesting effect in which flower-shaped confinement states are observed in the deformed region [Carrillo-Bastos et al., Phys. Rev. B 90 041411 (2014)]. To exploit such a deformation for various applications, tunable electronic features including a bandgap opening for semi-metallic structures are expected. Besides, the effects of disorders and external excitations also need to be considered. In this work, we present a systematic study on quantum transport of graphene ribbons with Gaussian deformation. Different levels of deformation are explored to find a universal behavior of the electron transmission. Using a tight-binding model in combination with Non-Equilibrium Green Functions formalism, we show that Gaussian deformation influences strongly the electronic properties of ribbons in which the electron transmission decreases remarkably in high energy regions even if small deformations are considered. Interestingly, it unveils that the first plateau of the transmission of semi-metallic armchair ribbons is just weakly affected in the case of small deformations. However, significant large Gaussian bumps can induce a strong drop of this plateau and a transport gap is formed. The transmission at the zero energy is found to decrease exponentially with increasing the size of the Gaussian bump. Moreover, the gap of semi-conducting ribbons is enlarged with large deformations. The opening or the widening of the transport gap in large deformed armchair structures is interpreted by a formation of a three-zone behavior along the transport direction of the hopping profile. On the other hand, a transport gap is not observed in zigzag ribbons regardless of the size of Gaussian bumps. This behavior is due to the strong localization of edge states at the energy point E = 0..., Comment: 25 pages, 12 figures
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- 2020
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20. A steep-slope MoS2-nanoribbon MOSFET based on an intrinsic cold-contact effect
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Logoteta, D., Pala, M. G., Choukroun, J., Dollfus, P., and Iannaccone, G.
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
We propose a steep-slope MoS2-nanoribbon field-effect transistor that exploits a narrow-energy conduction band to intrinsically filter out the thermionic tail of the electron energy distribution. We study the device operation principle and the performance dependence on the design parameters through atomistic self-consistent quantum simulations. Our results indicate that the device can provide high ION/IOFF ratios, compatible with electronic applications, albeit biased at ultralow voltages of around 0.1 V., Comment: 4 pages, 5 figures
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- 2020
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21. Contribution of whole genome sequencing in the molecular diagnosis of mosaic partial deletion of the NF1 gene in neurofibromatosis type 1
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Pacot, Laurence, Pelletier, Valerie, Chansavang, Albain, Briand-Suleau, Audrey, Burin des Roziers, Cyril, Coustier, Audrey, Maillard, Theodora, Vaucouleur, Nicolas, Orhant, Lucie, Barbance, Cécile, Lermine, Alban, Hamzaoui, Nadim, Hadjadj, Djihad, Laurendeau, Ingrid, El Khattabi, Laïla, Nectoux, Juliette, Vidaud, Michel, Parfait, Béatrice, Dollfus, Hélène, Pasmant, Eric, and Vidaud, Dominique
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- 2023
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22. Quality of life improvements following one year of setmelanotide in children and adult patients with Bardet–Biedl syndrome: phase 3 trial results
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Elizabeth Forsythe, Robert M. Haws, Jesús Argente, Philip Beales, Gabriel Á. Martos-Moreno, Hélène Dollfus, Costel Chirila, Ari Gnanasakthy, Brieana C. Buckley, Usha G. Mallya, Karine Clément, and Andrea M. Haqq
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BBS ,Genetic obesity ,IWQOL-Lite ,PedsQL ,Quality of life ,Setmelanotide ,Medicine - Abstract
Abstract Background Bardet–Biedl syndrome is a rare genetic disease associated with hyperphagia and early-onset, severe obesity. There is limited evidence on how hyperphagia and obesity affect health-related quality of life in patients with Bardet–Biedl syndrome, and on how management of these symptoms may influence disease burden. This analysis evaluated changes in health-related quality of life in adults and children with Bardet–Biedl syndrome in a Phase 3 trial following 1 year of setmelanotide treatment (ClinicalTrials.gov identifier: NCT03746522). Methods Patients with Bardet–Biedl syndrome and obesity received 52 weeks of treatment with setmelanotide and completed various self-reported health-related quality of life measures. Patients aged
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- 2023
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23. Sufentanil sublingual tablet system for enhanced recovery after total knee arthroplasty: a prospective observational case study
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Emmanuel Rineau, Benjamin Dumartinet, Emmanuel Samson, Apolline Dollfus, Corentin Aubourg, and Sigismond Lasocki
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Postoperative recovery ,Postoperative pain ,Prosthetic knee surgery ,Sufentanil sublingual tablet systems ,Patient-controlled analgesia ,Surgery ,RD1-811 - Abstract
Abstract Background Postoperative pain is one of the main factors that delays recovery after prosthetic knee surgery. The use of sufentanil sublingual tablet systems (SSTS) can effectively relieve postoperative pain, but their value in facilitating early mobilization has been little studied so far. Our aim here was to assess whether their use could facilitate recovery after knee arthroplasty in an enhanced recovery program. Case presentation In a prospective observational single-center study, thirty patients operated on for primary knee arthroplasty in the enhanced recovery pathway were included. Patients who received the SSTS (n=15) were compared with those who received an intravenous morphine patient-controlled analgesia (PCA) (n=15). Our recovery program included in particular the use of an adductor canal block, periarticular infiltration of local anesthetic by the surgeon, removal of the venous cannula from the recovery room if possible, the use of an SSTS when available or an IV morphine PCA otherwise, and early physiotherapy. Recovery parameters including the Timed-Up and Go test, pain scores at rest and on exertion, knee flexions, complications, and lengths of hospital stay were not significantly different between the two groups. However, the postoperative opioid consumption in morphine equivalents was significantly greater in the SL-sufentanil group and these patients had their venous cannula removed earlier than in IV-morphine group. Conclusion In our center, the use of a SSTS was suitable for treating postoperative pain after knee arthroplasty, but it did not improve early recovery in comparison with a morphine PCA.
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- 2022
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24. Study of phonon transport across Si/Ge interfaces using Full-Band phonon Monte Carlo simulation
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Le, N. D., Davier, B., Izitounene, N., Dollfus, P., and Saint-Martin, J.
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- 2022
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25. High performance Tunnel Field Effect Transistors based on in-plane transition metal dichalcogenide heterojunctions
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Choukroun, Jean, Pala, Marco, Fang, Shiang, Kaxiras, Efthimios, and Dollfus, Philippe
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Condensed Matter - Mesoscale and Nanoscale Physics ,Physics - Computational Physics - Abstract
In-plane heterojunction tunnel field effect transistors based on monolayer transition metal dichalcogenides are studied by means of self-consistent non-equilibrium Green's functions simulations and an atomistic tight-binding Hamiltonian. We start by comparing several heterojunctions before focusing on the most promising ones, i.e WTe2-MoS2 and MoTe2-MoS2. The scalability of those devices as a function of channel length is studied, and the influence of backgate voltages on device performance is analysed. Our results indicate that, by fine-tuning the design parameters, those devices can yield extremely low sub-threshold swings (below 5mV/decade) and Ion/Ioff ratios higher than 1e8 at a supply voltage of 0.3V, making them ideal for ultra-low power consumption., Comment: 10 pages
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- 2018
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26. Heat transfer in rough nanofilms and nanowires using Full Band Ab Initio Monte Carlo simulation
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Davier, B., Larroque, J., Dollfus, P., Chaput, L., Volz, S., Lacroix, D., and Saint-Martin, J.
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
The Boltzmann transport equation is one of the most relevant framework to study the heat transport at the nanoscale, beyond the diffusive regime and up to the micrometer-scale. In the general case of three-dimensional devices, the particle Monte Carlo approach of phonon transport is particularly powerful and convenient, and requires reasonable computational resources. In this work, we propose an original and versatile particle Monte Carlo approach parametrized by using ab-initio data. Both the phonon dispersion and the phonon-phonon scattering rates have been computed by DFT calculation in the entire 3D Brillouin zone. To treat the phonon transport at rough interfaces, a combination of specular and diffuse reflections has been implemented in phase space. Thermal transport has been investigated in nanowires and thin films made of cubic and hexagonal Silicon, including edge roughness, in terms of effective thermal conductivity, phonon band contributions and heat flux orientation. It is shown that the effective thermal conductivity in quasi-ballistic regime obtained from our Monte Carlo simulation cannot be accurately fitted by simple semi-analytical Matthiessen-like models and that spectral approaches are mandatory to get good results. Our Full Band approach shows that some phonon branches exhibiting a negative group velocity in some parts of the Brillouin zone may contribute negatively to the total thermal flux. Besides, the thermal flux clearly appears to be oriented along directions of high density of states. The resulting anisotropy of the heat flux is discussed together with the influence of rough interfaces.
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- 2018
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27. Full quantum simulation of Shockley–Read–Hall recombination in p-i-n and tunnel diodes
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Pilotto, A., Dollfus, P., Saint-Martin, J., and Pala, M.
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- 2022
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28. The Molecular Architecture of Native BBSome Obtained by an Integrated Structural Approach
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Chou, Hui-Ting, Apelt, Luise, Farrell, Daniel P, White, Susan Roehl, Woodsmith, Jonathan, Svetlov, Vladimir, Goldstein, Jaclyn S, Nager, Andrew R, Li, Zixuan, Muller, Jean, Dollfus, Hélène, Nudler, Evgeny, Stelzl, Ulrich, DiMaio, Frank, Nachury, Maxence V, and Walz, Thomas
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Biochemistry and Cell Biology ,Biological Sciences ,Underpinning research ,1.1 Normal biological development and functioning ,ADP-Ribosylation Factors ,Animals ,Cattle ,Cryoelectron Microscopy ,Homeostasis ,Humans ,Mass Spectrometry ,Microtubule-Associated Proteins ,Models ,Molecular ,Protein Conformation ,Protein Multimerization ,Retina ,BBSome ,cilia ,trafficking ,Biophysics - Abstract
The unique membrane composition of cilia is maintained by a diffusion barrier at the transition zone that is breached when the BBSome escorts signaling receptors out of cilia. Understanding how the BBSome removes proteins from cilia has been hampered by a lack of structural information. Here, we present a nearly complete Cα model of BBSome purified from cow retina. The model is based on a single-particle cryo-electron microscopy density map at 4.9-Å resolution that was interpreted with the help of comprehensive Rosetta-based structural modeling constrained by crosslinking mass spectrometry data. We find that BBSome subunits have a very high degree of interconnectivity, explaining the obligate nature of the complex. Furthermore, like other coat adaptors, the BBSome exists in an autoinhibited state in solution and must thus undergo a conformational change upon recruitment to membranes by the small GTPase ARL6/BBS3. Our model provides the first detailed view of the machinery enabling ciliary exit.
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- 2019
29. Expansion of the Human Phenotype Ontology (HPO) knowledge base and resources
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Köhler, Sebastian, Carmody, Leigh, Vasilevsky, Nicole, Jacobsen, Julius OB, Danis, Daniel, Gourdine, Jean-Philippe, Gargano, Michael, Harris, Nomi L, Matentzoglu, Nicolas, McMurry, Julie A, Osumi-Sutherland, David, Cipriani, Valentina, Balhoff, James P, Conlin, Tom, Blau, Hannah, Baynam, Gareth, Palmer, Richard, Gratian, Dylan, Dawkins, Hugh, Segal, Michael, Jansen, Anna C, Muaz, Ahmed, Chang, Willie H, Bergerson, Jenna, Laulederkind, Stanley JF, Yüksel, Zafer, Beltran, Sergi, Freeman, Alexandra F, Sergouniotis, Panagiotis I, Durkin, Daniel, Storm, Andrea L, Hanauer, Marc, Brudno, Michael, Bello, Susan M, Sincan, Murat, Rageth, Kayli, Wheeler, Matthew T, Oegema, Renske, Lourghi, Halima, Della Rocca, Maria G, Thompson, Rachel, Castellanos, Francisco, Priest, James, Cunningham-Rundles, Charlotte, Hegde, Ayushi, Lovering, Ruth C, Hajek, Catherine, Olry, Annie, Notarangelo, Luigi, Similuk, Morgan, Zhang, Xingmin A, Gómez-Andrés, David, Lochmüller, Hanns, Dollfus, Hélène, Rosenzweig, Sergio, Marwaha, Shruti, Rath, Ana, Sullivan, Kathleen, Smith, Cynthia, Milner, Joshua D, Leroux, Dorothée, Boerkoel, Cornelius F, Klion, Amy, Carter, Melody C, Groza, Tudor, Smedley, Damian, Haendel, Melissa A, Mungall, Chris, and Robinson, Peter N
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Biological Sciences ,Bioinformatics and Computational Biology ,Genetics ,Human Genome ,Networking and Information Technology R&D (NITRD) ,Rare Diseases ,Generic health relevance ,Good Health and Well Being ,Biological Ontologies ,Computational Biology ,Congenital Abnormalities ,Databases ,Genetic ,Genetic Predisposition to Disease ,Genetic Variation ,Humans ,Internet ,Knowledge Bases ,Phenotype ,Whole Genome Sequencing ,Environmental Sciences ,Information and Computing Sciences ,Developmental Biology ,Biological sciences ,Chemical sciences ,Environmental sciences - Abstract
The Human Phenotype Ontology (HPO)-a standardized vocabulary of phenotypic abnormalities associated with 7000+ diseases-is used by thousands of researchers, clinicians, informaticians and electronic health record systems around the world. Its detailed descriptions of clinical abnormalities and computable disease definitions have made HPO the de facto standard for deep phenotyping in the field of rare disease. The HPO's interoperability with other ontologies has enabled it to be used to improve diagnostic accuracy by incorporating model organism data. It also plays a key role in the popular Exomiser tool, which identifies potential disease-causing variants from whole-exome or whole-genome sequencing data. Since the HPO was first introduced in 2008, its users have become both more numerous and more diverse. To meet these emerging needs, the project has added new content, language translations, mappings and computational tooling, as well as integrations with external community data. The HPO continues to collaborate with clinical adopters to improve specific areas of the ontology and extend standardized disease descriptions. The newly redesigned HPO website (www.human-phenotype-ontology.org) simplifies browsing terms and exploring clinical features, diseases, and human genes.
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- 2019
30. Amelogenesis imperfecta: Next-generation sequencing sheds light on Witkop’s classification
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Agnes Bloch-Zupan, Tristan Rey, Alexandra Jimenez-Armijo, Marzena Kawczynski, Naji Kharouf, O-Rare consortium, Muriel de La Dure-Molla, Emmanuelle Noirrit, Magali Hernandez, Clara Joseph-Beaudin, Serena Lopez, Corinne Tardieu, Béatrice Thivichon-Prince, ERN Cranio Consortium, Tatjana Dostalova, Milan Macek, International Consortium, Mustapha El Alloussi, Leila Qebibo, Supawich Morkmued, Patimaporn Pungchanchaikul, Blanca Urzúa Orellana, Marie-Cécile Manière, Bénédicte Gérard, Isaac Maximiliano Bugueno, Virginie Laugel-Haushalter, Yves Alembik, Victorin Ahossi, Isabelle Bailleul-Forestier, Isabelle Blanchet, Ariane Berdal, Marie José Boileau, Nicolas Chassaing, François Clauss, Caroline Delfosse, Anne De-Saint-Martin, Jean-Christophe Dahlet, Bérénice Doray, Jean-Luc Davideau, Tiphaine Davit-Béal, Hélène Dollfus, Jean-Pierre Duprez, Muriel de La Dure Molla, Klauss Dieterich, Dominique Droz, Salima El Chehadeh, Olivier Etienne, Edouard Euvrard, Laurence Faivre, Benjamin Fournier, Elsa Garot, Bruno Grollemund, Nathalie Guffon-Fouilhoux, Mathilde Huckert, Bertand Isidor, Sophie Jung, Didier Lacombe, Alinoe Lavillaurex, Marine Lebrun, Bruno Leheup, Adeline Loing, Sandrine Marlin, Jean-Jacques Morrier, Michèle Muller-Bolla, Sylvie Odent, Marie Paule Gelle, Juliette Piard, Linda Pons, Béatrice Richard, Massimiliano Rossi, Prune Sadones, Elise Schaefer, Jean-Louis Sixou, Sylvie Soskin, Marion Strub, Annick Toutain, Alain Verloes, Frédéric Vaysse, and Delphine Wagner
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enamel ,amelogenesis imperfecta ,genetics ,rare diseases ,NGS ,next-generation sequencing ,Physiology ,QP1-981 - Abstract
Amelogenesis imperfecta (AI) is a heterogeneous group of genetic rare diseases disrupting enamel development (Smith et al., Front Physiol, 2017a, 8, 333). The clinical enamel phenotypes can be described as hypoplastic, hypomineralized or hypomature and serve as a basis, together with the mode of inheritance, to Witkop’s classification (Witkop, J Oral Pathol, 1988, 17, 547–553). AI can be described in isolation or associated with others symptoms in syndromes. Its occurrence was estimated to range from 1/700 to 1/14,000. More than 70 genes have currently been identified as causative.Objectives: We analyzed using next-generation sequencing (NGS) a heterogeneous cohort of AI patients in order to determine the molecular etiology of AI and to improve diagnosis and disease management.Methods: Individuals presenting with so called “isolated” or syndromic AI were enrolled and examined at the Reference Centre for Rare Oral and Dental Diseases (O-Rares) using D4/phenodent protocol (www.phenodent.org). Families gave written informed consents for both phenotyping and molecular analysis and diagnosis using a dedicated NGS panel named GenoDENT. This panel explores currently simultaneously 567 genes. The study is registered under NCT01746121 and NCT02397824 (https://clinicaltrials.gov/).Results: GenoDENT obtained a 60% diagnostic rate. We reported genetics results for 221 persons divided between 115 AI index cases and their 106 associated relatives from a total of 111 families. From this index cohort, 73% were diagnosed with non-syndromic amelogenesis imperfecta and 27% with syndromic amelogenesis imperfecta. Each individual was classified according to the AI phenotype. Type I hypoplastic AI represented 61 individuals (53%), Type II hypomature AI affected 31 individuals (27%), Type III hypomineralized AI was diagnosed in 18 individuals (16%) and Type IV hypoplastic-hypomature AI with taurodontism concerned 5 individuals (4%). We validated the genetic diagnosis, with class 4 (likely pathogenic) or class 5 (pathogenic) variants, for 81% of the cohort, and identified candidate variants (variant of uncertain significance or VUS) for 19% of index cases. Among the 151 sequenced variants, 47 are newly reported and classified as class 4 or 5. The most frequently discovered genotypes were associated with MMP20 and FAM83H for isolated AI. FAM20A and LTBP3 genes were the most frequent genes identified for syndromic AI. Patients negative to the panel were resolved with exome sequencing elucidating for example the gene involved ie ACP4 or digenic inheritance.Conclusion: NGS GenoDENT panel is a validated and cost-efficient technique offering new perspectives to understand underlying molecular mechanisms of AI. Discovering variants in genes involved in syndromic AI (CNNM4, WDR72, FAM20A … ) transformed patient overall care. Unravelling the genetic basis of AI sheds light on Witkop’s AI classification.
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- 2023
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31. Clinical, physiological and cerebral effects of a remote adapted physical activity program in patients with schizophrenia
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S. Dollfus
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Psychiatry ,RC435-571 - Abstract
Abstract: Background Physical activity (PA) has emerged as an interesting adjuvant non-pharmacological intervention in patients with schizophrenia (SZPs). The vast majority of programs are face-to-face without considering the patients’ physiological capacities and their difficulty to achieve the programs. The aim of this study was to demonstrate the efficacy of PA on clinical variables and brain plasticity. Its originality was to adapt PA on the cardiorespiratory and physical capacities (APA) and to deliver PA remotely by a videoconference coach (e-APA). Methods This longitudinal study included 35 SZPs (DSM-5) randomized either in an e-APA group or in a control group (health education training (e-HE)). Both programs were delivered in the same conditions, remotely via the web with a professional, for two 60-minute sessions per week during 16 weeks. Cardiorespiratory capacity measured by VO2max, clinical symptoms assessed with PANSS, BNSS and SNS, total hippocampus (HCP) volumes and their subfields, were evaluated in pre- (session 1) and post- interventions (session 2). High-resolution T1-weighted and two high-resolution T2w brain volumes were proceeded at session 1 and 2 (MRI 3-T, Philips). ANCOVAs were performed to determine intervention and/or diagnostic effects on relative variation (RV) of cardiorespiratory capacity, clinical symptoms and HCP volumes. Results The retention rate of SZPs in the study was 88.6%. SZPs of e-APA group presented a greater RV of VO2max (+7.3%) compared to SPZs-HE (-3.9%) (p = 0.024). No significant effect of the e-APA compared to the e-HE was demonstrated regarding the RV of the clinical symptoms. However, between 1 and 2 sessions, total PANSS scores, positive and general PANSS sub-scores significantly decreased in both groups while total SNS and BNSS scores only decreased in e-APA group. Finally, a positive and greater RV of the left subiculum volume was observed in e-APA (+3.4%) compared to e-HE (-2.5%) (p = 0.0005). Conclusion This study is the first one demonstrating the feasibility and acceptability of a remote APA program in SZPs with high participation rates. Our results show that e-APA induces brain plasticity reflected by an increase of HCP subfield volume and improves the cardiorespiratory capacity in SZPs. This study underlines that remote APA represents an innovative, original, safe and effective adjunctive therapeutic strategy in schizophrenia. Disclosure of Interest None Declared
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- 2023
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32. Self-assessment of auditory verbal hallucinations in schizophrenia; validation of a digital device
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S. Dollfus, F. Letourneur, L. Metivier, V. Moulier, and M. Rotharmel
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Psychiatry ,RC435-571 - Abstract
Introduction Auditory verbal hallucinations (AVH) are experienced by approximately 70% of patients with schizophrenia. At the present time, there are no self-evaluation scales for auditory verbal hallucinations. They would allow the patient to self-assess their hallucinations when they occur, taking into account the great variability over time. Moreover, self-assessment allows the patients to better recognize their symptoms and to be more engaged in their treatment. In this context, we have developed a digital device (MIMO) allowing the patient to self-evaluate his/her AVH and to declare his/her hallucinatory crisis at any time. This device contains a self-assessment of auditory verbal hallucinations (SAVH) with 13 questions, 9 of which concern the frequency, the severity, the content and the impact of hallucinations. These 9 questions are rated on a 5-point scale ranging from 0 (absent) to 5 (severe). The patients and practitioners can have an online feedback on the scores as well as on their temporal changes. Objectives The aim of this study was to validate the SAVH scale as well the digital tool, to demonstrate the acceptability by the patients and to prove the feasibility in using such a digital device (mobile phone or tablet). Methods Forty one patients with schizophrenia or schizoaffective disorder (DSM-5) with AVH loaded this application on their own mobile or on a loaned one. AVH was also assessed with the Auditory Hallucination Rating Scale associated with the Brief Psychiatric Rating Scale and the self-assessment of insight. Moreover, a questionnaire included a visual analogic scale on the global satisfaction of the device scoring from 0 (“Not at all satisfied”) to 10 (“Very satisfied”) and 22 questions concerning the conditions of use, the acceptability and the content of the app, its impact on mental health, and questions related to the declaration of hallucinatory crisis. Moreover, statistical analyses were carried out testing internal, external and construct validities of the SAVH. Results 56.1% and 36.6% of patients found the app to be easy and very easy to use, respectively. 61% and 29.3% of the patients considered that the questions were respectively rather adapted and very adapted to the evaluation of auditory hallucinations. 46.3% of patients found the questions quite easy to understand. The majority of patients felt that the MIMO app could be useful to them. Overall satisfaction was 8.073+-3.8 indicating very good overall patient satisfaction of the app. Statistical tests revealed significant convergence and divergence validities as well as good internal consistency of the SAVH. Conclusions This study demonstrated good psychometric properties of the SAVH and very good acceptability of this kind of assessment by digital device in patients with schizophrenia. Such a device can be quite useful to assess the efficacy of the treatment of AVH and to increase the patient’s empowerment. Disclosure of Interest None Declared
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- 2023
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33. Impact of adapted physical activity on hippocampal N-Acetyl Aspartate in patients with schizophrenia
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L. Metivier, F. Briend, M. Tréhout, L. Bigot, G. Quarck, A. Herbinet, E. Leroux, and S. Dollfus
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Psychiatry ,RC435-571 - Abstract
Introduction Adapted physical activity (APA) has beneficial neurobiological impact but the underlying pathophysiological mechanisms remain poorly described. APA is currently recognized as an adjuvant therapy to antipsychotic treatments in patients with schizophrenia (SCZs) to reduce the severity of negative symptoms and cognitive impairment. SCZs exhibit hippocampal N-acetylaspartate (NAA) reduction, a marker of neuronal viability and integrity whose concentrations can be assessed by proton magnetic resonance spectroscopy (1H-MRS). Objectives The purpose of this study was to evaluate the impact of remote physical activity (e-APA) via the web on the NAA relative variations in the left hippocampus in SCZs compared to a patient control group benefiting from an health education program (HE). This study concerns one of the secondary objectives of the PEPsy V@SI study co-financed by the Pierre Deniker Foundation, the European Union and the Normandy Region within the framework of the FEDER/FSE 2014-2020 operational program. Methods Thirty-five SCZs were randomized in the e-APA active group or in the control group (HE). Participants received the interventions during 16 weeks, with two visioconference sessions per week. A 1H-MRS sequence positioned on the left hippocampus (MRI-3T) was acquired before and after both interventions. Absolute NAA concentrations in the left hippocampus were obtained using Osprey software after partial volume correction. After checking the quality criteria, the spectra of 6 SCZs in the e-APA group and 8 SCZs in the HE group were analyzed. To test the difference between interventions on the NAA relative variations, a Wilcoxon-Mann-Whitney test and effect size were performed. Paired Wilcoxon tests were used in each group before and after the interventions. Results No significant difference was found in NAA relative variations in the left hippocampus between the e-APA group and the HE group (p = 0.18), although the effect size was 0.38 (considered as moderate). However, a trend towards an increase of NAA was observed in the e-APA group (before intervention: 12.08 International Units (I.U); after: 13.81 I.U) (p = 0.06) but not in the HE group (before intervention: 13.75 I.U ; after: 13.85 I.U) (p = 0.84). Conclusions Our results showed a NAA significant increase in SCZs after an e-APA program, indicating a beneficial impact of e-APA on neuronal viability that might reflect an hippocampal plasticity. However, this increase did not differ significantly between active and control groups probably due to a weak statistical power. Disclosure of Interest L. Metivier: None Declared, F. Briend: None Declared, M. Tréhout: None Declared, L. Bigot: None Declared, G. Quarck: None Declared, A. Herbinet: None Declared, E. Leroux: None Declared, S. Dollfus Consultant of: Fabre,Gedeon,Roche and Takeda, inivited Conferences by Lundbeck, Otsuka, Janssen ; at contracts with Prophase MedAvances and NeuroCogTrials
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- 2023
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34. Avalanche breakdown and quenching in Ge SPAD using 3D Monte Carlo simulation
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Dollfus, P., Saint-Martin, J., Cazimajou, T., Helleboid, R., Pilotto, A., Rideau, D., Bournel, A., and Pala, M.
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- 2022
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35. Phonon-assisted transport in van der Waals heterostructure tunnel devices
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M'foukh, A., Saint-Martin, J., Dollfus, P., and Pala, M.
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- 2022
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36. Natural history of NF1 c.2970_2972del p.(Met992del): confirmation of a low risk of complications in a longitudinal study
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Forde, Claire, Burkitt-Wright, Emma, Turnpenny, Peter D., Haan, Eric, Ealing, John, Mansour, Sahar, Holder, Muriel, Lahiri, Nayana, Dixit, Abhijit, Procter, Annie, Pacot, Laurence, Vidaud, Dominique, Capri, Yline, Gerard, Marion, Dollfus, Hélène, Schaefer, Elise, Quelin, Chloé, Sigaudy, Sabine, Busa, Tiffany, Vera, Gabriella, Damaj, Lena, Messiaen, Ludwine, Stevenson, David A., Davies, Peter, Palmer-Smith, Sheila, Callaway, Alison, Wolkenstein, Pierre, Pasmant, Eric, and Upadhyaya, Meena
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- 2022
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37. Sufentanil sublingual tablet system for enhanced recovery after total knee arthroplasty: a prospective observational case study
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Rineau, Emmanuel, Dumartinet, Benjamin, Samson, Emmanuel, Dollfus, Apolline, Aubourg, Corentin, and Lasocki, Sigismond
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- 2022
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38. High thermoelectric performance of graphite nanofibers
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Tran, Van-Truong, Saint-Martin, Jérôme, Dollfus, Philippe, and Volz, Sebastian
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
Graphite nanofibers (GNFs) have been demonstrated to be a promising material for hydrogen storage and heat management in electronic devices. Here, by means of first-principles and transport simulations, we show that GNFs can also be an excellent material for thermoelectric applications thanks to the interlayer weak van der Waals interaction that induces low thermal conductance and a step-like shape in the electronic transmission with mini-gaps, which are necessary ingredients to achieve high thermoelectric performance. This study unveils that the platelet form of GNFs in which graphite layers are perpendicular to the fiber axis can exhibit outstanding thermoelectric properties with a figure of merit ZT reaching 3.55 in a 0.5 nm diameter fiber and 1.1 for a 1.1 nm diameter one. Interestingly, by introducing 14C isotope doping, ZT can even be enhanced up to more than 5, and more than 8 if we include the effect of finite phonon mean-free path, which demonstrates the amazing thermoelectric potential of GNFs., Comment: 25 pages, 6 figures
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- 2017
39. Third nearest neighbor parameterized tight biding model for graphene nano-ribbons
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Tran, Van-Truong, Saint-Martin, Jérôme, Dollfus, Philippe, and Volz, Sebastian
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
The ab initio band structure of 2D graphene sheet is well reproduced by the third nearest neighbor tight binding model proposed by Reich et al [Phys. Rev. B 66, 035412]. For ribbon structures, the existing sets of tight binding parameters can successfully explain semi-conducting behavior of all armchair ribbon structures. However, they are still failing in describing accurately the slope of the bands while this feature is directly associated to the group velocity and the effective mass of electrons. In this work, both density functional theory and tight binding calculations were performed and a new set of tight binding parameters up to the third nearest neighbors including overlap terms is introduced. The results obtained with this model offer excellent agreement with the predictions of the density functional theory in most cases of ribbon structures, even in the high-energy region. Moreover, this set can induce electron-hole asymmetry as manifested in density functional theory. Relevant outcomes are also demonstrated for armchair ribbons of various widths as well as for zigzag structures, thus opening a route for multi-scale simulations., Comment: 18 pages, 6 figures, 1 table
- Published
- 2017
40. Comprehensive Modeling and Characterization of Photon Detection Efficiency and Jitter Tail in Advanced SPAD Devices
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Remi Helleboid, Denis Rideau, Jeremy Grebot, Isobel Nicholson, Norbert Moussy, Olivier Saxod, Marie Basset, Antonin Zimmer, Bastien Mamdy, Dominique Golanski, Megan Agnew, Sara Pellegrini, Mathieu Sicre, Christel Buj, Guillaume Marchand, Jerome Saint-Martin, Marco Pala, and Philippe Dollfus
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Avalanche breakdown probability ,breakdown voltage ,jitter ,photon detection efficiency (PDE) ,single-photon avalanche diode (SPAD) ,technology computer-aided design (TCAD) ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 - Abstract
A new method to reliably simulate the PDE and jitter tail for realistic three-dimensional SPAD devices is presented. The simulation method is based on the use of electric field lines to mimic the carriers’ trajectories, and on one-dimensional models for avalanche breakdown probability and charges transport. This approach allows treating a three-dimensional problem as several one-dimensional problems along each field line. The original approach is applied to the McIntyre model for avalanche breakdown probability to calculate PDE, but also for jitter prediction using a dedicated advection-diffusion model. The results obtained numerically are compared with an extensive series of measurements and show a good agreement on a wide variety of device designs.
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- 2022
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41. Examining transcranial random noise stimulation as an add-on treatment for persistent symptoms in schizophrenia (STIM’Zo): a study protocol for a multicentre, double-blind, randomized sham-controlled clinical trial
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Jerome Brunelin, Marine Mondino, Julie Haesebaert, Jerome Attal, Michel Benoit, Marie Chupin, Sonia Dollfus, Wissam El-Hage, Filipe Galvao, Renaud Jardri, Pierre Michel Llorca, Laurent Magaud, Marion Plaze, Anne Marie Schott-Pethelaz, Marie-Françoise Suaud-Chagny, David Szekely, Eric Fakra, and Emmanuel Poulet
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Schizophrenia ,Noninvasive brain stimulation ,tDCS ,tRNS ,Hallucination ,Negative symptoms ,Medicine (General) ,R5-920 - Abstract
Abstract Background One out of three patients with schizophrenia failed to respond adequately to antipsychotics and continue to experience debilitating symptoms such as auditory hallucinations and negative symptoms. The development of additional therapeutic approaches for these persistent symptoms constitutes a major goal for patients. Here, we develop a randomized-controlled trial testing the efficacy of high-frequency transcranial random noise stimulation (hf-tRNS) for the treatment of resistant/persistent symptoms of schizophrenia in patients with various profiles of symptoms, cognitive deficits and illness duration. We also aim to investigate the biological and cognitive effects of hf-tRNS and to identify the predictors of clinical response. Methods In a randomized, double-blind, 2-arm parallel-group, controlled, multicentre study, 144 patients with schizophrenia and persistent symptoms despite the prescription of at least one antipsychotic treatment will be randomly allocated to receive either active (n = 72) or sham (n = 72) hf-tRNS. hf-tRNS (100–500 Hz) will be delivered for 20 min with a current intensity of 2 mA and a 1-mA offset twice a day on 5 consecutive weekdays. The anode will be placed over the left dorsolateral prefrontal cortex and the cathode over the left temporoparietal junction. Patients’ symptoms will be assessed prior to hf-tRNS (baseline), after the 10 sessions, and at 1-, 3- and 6-month follow-up. The primary outcome will be the number of responders defined as a reduction of at least 25% from the baseline scores on the Positive and Negative Syndrome Scale (PANSS) after the 10 sessions. Secondary outcomes will include brain activity and connectivity, source monitoring performances, social cognition, other clinical (including auditory hallucinations) and biological variables, and attitude toward treatment. Discussion The results of this trial will constitute a first step toward establishing the usefulness of hf-tRNS in schizophrenia whatever the stage of the illness and the level of treatment resistance. We hypothesize a long-lasting effect of active hf-tRNS on the severity of schizophrenia symptoms as compared to sham. This trial will also have implications for the use of hf-tRNS as a preventive intervention of relapse in patients with schizophrenia. Trial registration ClinicalTrials.gov NCT02744989. Prospectively registered on 20 April 2016
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- 2021
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42. Validity and reliability of a Persian version of the self- evaluation of negative symptoms (SNS)
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Shahrzad Mazhari, Anahita Karamooz, Mahin Eslami Shahrbabaki, Farzaneh Jahanbakhsh, and Sonia Dollfus
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Negative symptoms ,Persian ,Psychometrics ,Schizophrenia ,SNS ,Psychiatry ,RC435-571 - Abstract
Abstract Aim The Self-evaluation of Negative Symptoms (SNS) has been developed to allow schizophrenia patients to evaluate themselves in five dimensions of negative symptoms. The present study aimed to examine psychometric properties of the Persian version of SNS. Methods A group of 50 patients with schizophrenia and a group of 50 healthy controls received the Persian-SNS. Severity of negative symptoms were evaluated by the Scale for Assessment of Negative symptoms (SANS) and the Brief Psychiatric Rating Scale (BPRS). Results The results showed that the Cronbach’s alpha for the Persian SNS was 0.95. The Persian-SNS and its subscales showed significant positive correlations with the total SANS score and SANS subscales as well as BPRS negative subscale, thus confirming the validity of the scale. Finally, the Persian-SNS showed the ability to discriminate patients with schizophrenia from healthy controls. Conclusion The acceptable properties of the Persian version of SNS demonstrated that it is a practical tool for screening negative symptoms in Persian-speaking schizophrenia patients.
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- 2021
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43. Sleep-Disordered Breathing, Quality of Sleep and Chronotype in a Cohort of Adult Patients with Bardet–Biedl Syndrome
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Dormegny L, Velizarova R, Schroder CM, Kilic-Huck U, Comtet H, Dollfus H, Bourgin P, and Ruppert E
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bardet-biedl syndrome ,ciliopathy ,sleep disordered breathing ,sleep apnea syndrome ,chronotype ,circadian rhythm sleep wake disorder ,Psychiatry ,RC435-571 ,Neurophysiology and neuropsychology ,QP351-495 - Abstract
Léa Dormegny,1,2 Reana Velizarova,1 Carmen M Schroder,1,3 Ulker Kilic-Huck,1,3 Henri Comtet,1,3 Hélène Dollfus,4 Patrice Bourgin,1,3 Elisabeth Ruppert1,3 1Centre des Troubles du Sommeil - CIRCSom, Hôpital Civil, University of Strasbourg, Strasbourg, 67091, France; 2Department of Ophthalmology, Hôpital Civil, University of Strasbourg, Strasbourg, 67091, France; 3Institute for Cellular and Integrative Neurosciences, CNRS - UPR 3212, Strasbourg, 67000, France; 4Centre des Affections Rares en Génétique Ophtalmologique (CARGO), University of Strasbourg, Strasbourg, 67091, FranceCorrespondence: Elisabeth RuppertCentre des Troubles du Sommeil - CIRCSom - Hôpital Civil, 1, place de l’Hôpital, BP 426, Cedex, Strasbourg, 67091, FranceTel +33 3 88 11 64 30Fax +33 3 88 11 51 53Email elisabeth.ruppert@chru-strasbourg.frObjective/Background: Bardet–Biedl syndrome (BBS) is a rare but well-recognized ciliopathy with high genetic and phenotypic heterogeneity. Cardinal features include obesity, diabetes and high blood pressure (HBP), which are often associated with sleep-disordered breathing. Also, the high prevalence of blindness due to retinal dystrophy could affect circadian sleep–wake rhythms. We characterized in this cohort of adult BBS patients sleep-disordered breathing, sleep quality, daytime sleepiness and chronotype.Patients and Methods: Thirty-two patients with genetically confirmed BBS were included in this observational single center study. Overnight respiratory polygraphy was performed for sleep apnea syndrome (SAS) in 30 patients. Quality of sleep, daytime sleepiness, fatigue and chronotype were assessed in 25 patients using Pittsburgh sleep quality index (PSQI), 14-day sleep diary (SD), Epworth sleepiness scale (ESS), Pichot fatigue scale (PFS) and Horne and Ostberg morningness-eveningness questionnaire (MEQ).Results: Patients’ mean age was 32± 11 years and mean BMI 32.6± 7.7 kg/m2. Eleven (35%) patients had HBP and 7 (22%) diabetes. Moderate to severe sleep apnea syndrome (SAS) was present in 5 (17%) and was not associated with altered sleep, daytime sleepiness or fatigue. Most of the patients (63%) evaluated their sleep as of good quality (PSQI ≤ 5). Median scores of sleep quality, daytime sleepiness and fatigue were normal (PSQI of 3.0 [2.0– 6.0], ESS of 9.0 [6.0– 13.0] and PFS of 8.0 [3.0– 13.0], respectively). Predominant chronotypes according to MEQ were either “intermediate” (57%) or “moderate morning” (29%). None had a free running sleep–wake cycle. 14-day SD revealed overall few awakenings at night and low daytime napping.Conclusions: Given the cardiovascular risk factors, systematic screening for SAS should be considered in BBS patients, regardless of sleep and daytime vigilance complaints. None of these highly visually impaired patients had a circadian sleep–wake rhythm disorder. Further objective assessments are needed to better characterize sleep and circadian rhythms in BBS patients.Keywords: Bardet–Biedl syndrome, ciliopathy, sleep disordered breathing, sleep apnea syndrome, chronotype, circadian rhythm sleep wake disorder
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- 2021
44. Characterization of SSBP1-related optic atrophy and foveopathy
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Isabelle Meunier, Béatrice Bocquet, Sabine Defoort-Dhellemmes, Vasily Smirnov, Carl Arndt, Marie Christine Picot, Hélène Dollfus, Majida Charif, Isabelle Audo, Hélèna Huguet, Xavier Zanlonghi, and Guy Lenaers
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Medicine ,Science - Abstract
Abstract Dominant optic atrophy (DOA) is genetically heterogeneous and most commonly caused by mutations in OPA1. To distinguish between the classical OPA1-related and the recently identified SSBP1-related DOAs, the retina and fovea of 27 patients carrying the SSBP1 p.Arg38Gln variant were scrutinized using 20° × 20° macular cube and 30° and 55° field fundus autofluorescence photographs. Age of onset, visual acuity, retinal nerve fiber layer and macular thicknesses were recorded. Three SSBP1-patients were asymptomatic, 10 had isolated DOA, and 12 had a combined DOA plus foveopathy. The foveopathy, with a tiny defect of the ellipsoid and interdigitation lines, was similar in all patients, independent of age. There were no significant statistical differences in terms of visual acuity and SD-OCT measurements between patients with isolated DOA (mean visual acuity in decimals: 0.54 ± 0.41) and those with combined foveopathy (0.50 ± 0.23). Two patients over 50 years of age developed a progressive rod-cone dystrophy, leading to severe visual impairment. SSBP1-related DOA shares similarities with OPA1-related DOA with an incomplete penetrance and an early childhood visual impairment. Nevertheless, the presence of a congenital foveopathy with no impact on visual acuity is a major criterion to distinguish SSBP1 cases and orient the appropriate genetic analysis.
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- 2021
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45. A new mixed hardening methodology applied to a 28 nm FDSOI 32-bits DSP subjected to gamma radiation
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Acuña, A. Ureña, Armani, J.M., Slimani, M., Miro-Panades, I., and Dollfus, P.
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- 2021
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46. Optimizing isotope and vacancy engineering in graphene ribbons to enhance the thermoelectric performance without degrading the electronic properties
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Tran, Van-Truong, Saint-Martin, Jérôme, Dollfus, Philippe, and Volz, Sebastian
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
The enhancement of thermoelectric figure of merit ZT requires to either increase the power factor or reduce the phonon conductance, or even both. In graphene, the high phonon thermal conductivity is the main factor limiting the thermoelectric conversion. The common strategy to enhance ZT is therefore to introduce phonon scatterers to suppress the phonon conductance while retaining high electrical conductance and Seebeck coefficient. Although thermoelectric performance is eventually enhanced, all studies based on this strategy show a significant reduction of the electrical conductance, most often leading to a lower electronic performance. In this study we show that appropriate sources of disorder, including isotopes and vacancies at lowest electron density positions, can be used as phonon scatterers to reduce the phonon conductance in graphene ribbons without degrading the electrical conductance, particularly in the low-energy region which is the most important range for device operation. By means of atomistic calculations using semi-empirical Tight-Binding and Force Constant models in combination with Non-Equilibrium Green function formalism, we show that the natural electronic properties of graphene ribbons can be fully preserved while their thermoelectric efficiency is strongly enhanced. For ribbons of width M = 5 dimer lines, room-temperature ZT is enhanced from less than 0.26 for defect-free ribbons to more than 2.5. This study is likely to set the milestones of a new generation of nano-devices with dual electronic, thermoelectric functionalities., Comment: 26 pages, 10 figures, 2 tables
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- 2016
47. Valley filtering and electronic optics using polycrystalline graphene
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Nguyen, Viet Hung, Dechamps, Samuel, Dollfus, Philippe, and Charlier, Jean-Christophe
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
In this Letter, both the manipulation of valley-polarized currents and the optical-like behaviors of Dirac fermions are theoretically explored in polycrystalline graphene. When strain is applied, the misorientation between two graphene domains separated by a grain boundary can result in a mismatch of their electronic structures. Such a discrepancy manifests itself in a strong breaking of the inversion symmetry, leading to perfect valley polarization in a wide range of transmission directions. In addition, these graphene domains act as different media for electron waves, offering the possibility to modulate and obtain negative refraction indexes., Comment: 5 pages, 4 figures, revised
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- 2016
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48. Transport properties through graphene grain boundaries: strain effects versus lattice symmetry
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Nguyen, Viet Hung, Hoang, Trinh Xuan, Dollfus, Philippe, and Charlier, Jean-Christophe
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
As most materials available in macroscopic quantities, graphene appears in a polycrystalline form and thus contains grain boundaries. In the present work, the effect of uniaxial strain on the electronic transport properties through graphene grain boundaries is investigated using atomistic simulations. A systematic picture of the transport properties with respect to the strain and the lattice symmetry of graphene domains on both sides of the boundary is provided. In particular, it is shown that the strain engineering can be used to open a finite transport gap in all graphene systems where two domains exhibit different orientations. This gap value is found to depend on the strain magnitude, on the strain direction and on the lattice symmetry of graphene domains. By choosing appropriately the strain direction, a large transport gap of a few hundred meV can be achieved when applying a small strain of only a few percents. For a specific class of graphene grain boundary systems, the strain engineering can also be used to reduce the scattering on defects and hence to significantly enhance the conductance. With a large strain-induced gap, these graphene heterostructures are proposed to be possible candidates for highly sensitive strain sensors, flexible transistors and p-n junctions with a strong non-linear I-V characteristics., Comment: 26 pages, 12 figures, submitted
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- 2016
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49. Cystoid maculopathy is a frequent feature of Cohen syndrome-associated retinopathy
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Pierre-Henry Gabrielle, Laurence Faivre, Isabelle Audo, Xavier Zanlonghi, Hélène Dollfus, Alberta A. H. J. Thiadens, Christina Zeitz, Grazia M. S. Mancini, Yaumara Perdomo, Saddek Mohand-Saïd, Eléonore Lizé, Vincent Lhussiez, Emeline F. Nandrot, Niyazi Acar, Catherine Creuzot-Garcher, José-Alain Sahel, Muhammad Ansar, Christel Thauvin-Robinet, Laurence Duplomb, and Romain Da Costa
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Medicine ,Science - Abstract
Abstract Cohen syndrome (CS) is a rare syndromic form of rod-cone dystrophy. Recent case reports have suggested that cystoid maculopathy (CM) could affect CS patients with an early onset and high prevalence. Our study aims at improving our understanding and management of CM in CS patients through a retrospective case series of ten CS patients with identified pathogenic variants in VPS13B. Longitudinal optical coherence tomography (OCT) imaging was performed and treatment with carbonic anhydrase inhibitors (CAI) was provided to reduce the volume of cystoid spaces. CM affected eight out of ten patients in our cohort. The youngest patient showed a strong progression of macular cysts from the age of 4.5 to 5 years despite oral CAI medication. Other teenage and young adult patients showed stable macular cysts with and without treatment. One patient showed a moderate decrease of cystoid spaces in the absence of treatment at 22 years of age. Through a correlative analysis we found that the volume of cystoid spaces was positively correlated to the thickness of peripheral and macular photoreceptor-related layers. This study suggests that CAI treatments may not suffice to improve CM in CS patients, and that CM may resolve spontaneously during adulthood as photoreceptor dystrophy progresses.
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- 2021
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50. Enhancement of thermoelectric performance in Graphene/BN heterostructures
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Tran, Van-Truong, Martin, Jérôme Saint, and Dollfus, Philippe
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Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
The thermoelectric properties of in plane heterostructures made of Graphene and hexagonal Boron Nitride (BN) have been investigated by means of atomistic simulation. The heterostructures consist in armchair graphene nanoribbons to the sides of which BN flakes are periodically attached. This arrangement generates a strong mismatch of phonon modes between the different sections of the ribbons, which leads to a very small phonon conductance, while the electron transmission is weakly affected. In combination with the large Seebeck coefficient resulting from the BN-induced bandgap opening or broadening, it is shown that large thermoelectric figure of merit ZT > 0.8 can be reached in perfect structures at relatively low Fermi energy, depending on the graphene nanoribbon width. The high value ZT = 1.48 may even be achieved by introducing appropriately vacancies in the channel, as a consequence of further degradation of the phonon conductance., Comment: 10 pages, 8 figures, 1 table
- Published
- 2015
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