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151. Concept of Lattice Mismatch and Emergence of Surface States in Two-dimensional Hybrid Perovskite Quantum Wells

Author

Kepenekian, Mikaël, primary, Traore, Boubacar, additional, Blancon, Jean-Christophe, additional, Pedesseau, Laurent, additional, Tsai, Hsinhan, additional, Nie, Wanyi, additional, Stoumpos, Constantinos C., additional, Kanatzidis, Mercouri G., additional, Even, Jacky, additional, Mohite, Aditya D., additional, Tretiak, Sergei, additional, and Katan, Claudine, additional

Published
2018
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152. Making and breaking the exciton in layered halide hybrid perovskites

Author

Kepenekian, Mikael, primary, Mohite, Aditya, additional, Blancon, Jean-Christophe, additional, Tsai, Hsinhan, additional, Nie, Wanyi, additional, Stoumpos, Konstantinos, additional, Traore, Boubacar, additional, Katan, Claudine, additional, Tretiak, Sergei, additional, Kanatzidis, Mercouri, additional, Even, Jacky, additional, and Pedesseau, Laurent, additional

Published
2018
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153. Halide Perovskites: Recent Advances in Optoelectronic Properties from Atomic Scale Modelling

Author

Katan, Claudine, primary, Even, Jacky, additional, Képénékian, Mikaël, additional, Pedesseau, Laurent, additional, Blancon, Jean-Christophe, additional, Nie, Wanyi, additional, Traore, Boubacar, additional, Tretiak, Sergei, additional, Stoumpos, Constantinos, additional, Kanatzidis, Mercouri, additional, Mohite, Aditya, additional, and Tsai, Hsinhan, additional

Published
2018
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154. NK cells inhibit Plasmodium falciparum growth in red blood cells via antibody-dependent cellular cytotoxicity

Author

Arora, Gunjan, primary, Hart, Geoffrey T, additional, Manzella-Lapeira, Javier, additional, Doritchamou, Justin YA, additional, Narum, David L, additional, Thomas, L Michael, additional, Brzostowski, Joseph, additional, Rajagopalan, Sumati, additional, Doumbo, Ogobara K, additional, Traore, Boubacar, additional, Miller, Louis H, additional, Pierce, Susan K, additional, Duffy, Patrick E, additional, Crompton, Peter D, additional, Desai, Sanjay A, additional, and Long, Eric O, additional

Published
2018
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155. Author response: NK cells inhibit Plasmodium falciparum growth in red blood cells via antibody-dependent cellular cytotoxicity

Author

Arora, Gunjan, primary, Hart, Geoffrey T, additional, Manzella-Lapeira, Javier, additional, Doritchamou, Justin YA, additional, Narum, David L, additional, Thomas, L Michael, additional, Brzostowski, Joseph, additional, Rajagopalan, Sumati, additional, Doumbo, Ogobara K, additional, Traore, Boubacar, additional, Miller, Louis H, additional, Pierce, Susan K, additional, Duffy, Patrick E, additional, Crompton, Peter D, additional, Desai, Sanjay A, additional, and Long, Eric O, additional

Published
2018
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156. Natural killer cells inhibit Plasmodium falciparum growth in red blood cells via antibody-dependent cellular cytotoxicity

Author

Arora, Gunjan, primary, Hart, Geoffrey T., additional, Manzella-Lapeira, Javier, additional, Doritchamou, Justin Y.A., additional, Narum, David L., additional, Thomas, L. Michael, additional, Brzostowski, Joseph, additional, Rajagopalan, Sumati, additional, Doumbo, Ogobara K., additional, Traore, Boubacar, additional, Miller, Louis H., additional, Pierce, Susan K., additional, Duffy, Patrick E., additional, Crompton, Peter D., additional, Desai, Sanjay A., additional, and Long, Eric O., additional

Published
2018
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157. Composite Nature of Layered Hybrid Perovskites: Assessment on Quantum and Dielectric Confinements and Band Alignment

Author

Traore, Boubacar, primary, Pedesseau, Laurent, additional, Assam, Linda, additional, Che, Xiaoyang, additional, Blancon, Jean-Christophe, additional, Tsai, Hsinhan, additional, Nie, Wanyi, additional, Stoumpos, Constantinos C., additional, Kanatzidis, Mercouri G., additional, Tretiak, Sergei, additional, Mohite, Aditya D., additional, Even, Jacky, additional, Kepenekian, Mikaël, additional, and Katan, Claudine, additional

Published
2018
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158. Electronic properties of hybrid organic and inorganic perovskites

Author

Traore, Boubacar, Pedesseau, Laurent, Kepenekian, Mikael, Even, Jacky, Katan, Claudine, Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut des Fonctions Optiques pour les Technologies de l'informatiON (Institut FOTON), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS), European Project: 687008,H2020,H2020-FETOPEN-2014-2015-RIA,GOTSolar(2016), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-Centre National de la Recherche Scientifique (CNRS)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT), École Nationale Supérieure des Sciences Appliquées et de Technologie (ENSSAT)-IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)

Subjects
[CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry
Abstract

International audience; In this poster we, first, present ABINIT based DFT results of the optoelectronic properties of CH3NH3PbI3 and CH3NH3BCl3 (B=Pb, Sn, Ge) hybrid organic-inorganic perovskites (HOP). For CH3NH3MCl3 HOP, the pseudocubic high temperature reference HOP structure (Pm-3m) was used to compare spin-orbit coupling (SOC) induced effect due to the metal atom B.[1-3]Next, we present 2D layered HOP, which received a renewed interest in recent years due to increased stability under lighting conditions and resistance to humidity and moisture. Their electronic properties show their potential in photovoltaic and optoelectronic applications.[4]

Published
2017

159. Theoretical insights and experimental characterization of HfO 2 -based OxRRAMs operation

Author

Traore, Boubacar, Blaise, Patrick, Vianello, E., Sklenard, B., Institut des Sciences Chimiques de Rennes (ISCR), Université de Rennes (UR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Fondation Nanosciences, Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées - Rennes (INSA Rennes), and Institut National des Sciences Appliquées (INSA)-Université de Rennes (UNIV-RENNES)-Institut National des Sciences Appliquées (INSA)-Ecole Nationale Supérieure de Chimie de Rennes (ENSCR)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Oxygen vacancy (Vo) diffusion, HfTiO, Doping/alloying, Data retention, Ti/HfO 2 interface, [CHIM]Chemical Sciences, HfAlO, Conductive filament (CF), ComputingMilieux_MISCELLANEOUS, HfO 2
Abstract

International audience

Published
2017
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161. Layered/3D Halide Hybrid Perovskite Semiconductors: Advances and Promises

Author

Pedesseau, Laurent, primary, Kepenekian, Mikael, additional, Traore, Boubacar, additional, Robles, Roberto, additional, Fang, Hong Hua, additional, Loi, Maria A, additional, Tsai, Hsinhan, additional, Sapori, Daniel, additional, Blancon, Jean Christophe, additional, Neukirch, Amanda, additional, Tretiak, Sergei, additional, Mohite, Aditya, additional, Katan, Claudine, additional, Even, Jacky, additional, and Nie, Wanyi, additional

Published
2017
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162. Critical Role of Interface and Crystallinity on the Performance and Photostability of Perovskite Solar Cell on Nickel Oxide

Author

Nie, Wanyi, primary, Tsai, Hsinhan, additional, Blancon, Jean‐Christophe, additional, Liu, Fangze, additional, Stoumpos, Costas C., additional, Traore, Boubacar, additional, Kepenekian, Mikael, additional, Durand, Olivier, additional, Katan, Claudine, additional, Tretiak, Sergei, additional, Crochet, Jared, additional, Ajayan, Pulickel M., additional, Kanatzidis, MercouriG., additional, Even, Jacky, additional, and Mohite, Aditya D., additional

Published
2017
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163. Making and breaking of the exciton in layered halide hybrid perovskites

Author

Kepenekian, Mikaël, primary, Mohite, Aditya, additional, Blancon, Jean-Christophe, additional, Tsai, Hsinhan, additional, Nie, Wanyi, additional, Stoumpos, Constantinos, additional, Traore, Boubacar, additional, Katan, Claudine, additional, Tretiak, Sergei, additional, Kanatzidis, Mercouri, additional, Even, Jacky, additional, and Pedesseau, Laurent, additional

Published
2017
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164. Malaria-induced interferon-γ drives the expansion of Tbethi atypical memory B cells

Author

Obeng-Adjei, Nyamekye, primary, Portugal, Silvia, additional, Holla, Prasida, additional, Li, Shanping, additional, Sohn, Haewon, additional, Ambegaonkar, Abhijit, additional, Skinner, Jeff, additional, Bowyer, Georgina, additional, Doumbo, Ogobara K., additional, Traore, Boubacar, additional, Pierce, Susan K., additional, and Crompton, Peter D., additional

Published
2017
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167. Longitudinal analysis of Plasmodium falciparum-specific atypical and classical memory B cell responses to natural malaria infection in children and adults

Author

Hopp, Christine, primary, Krishnamurty, Akshay T, additional, Portugal, Silvia, additional, Thouvenel, Chris, additional, Doumbo, Ogobara K, additional, Traore, Boubacar, additional, Pierce, Susan K, additional, Rawlings, David J, additional, Pepper, Marion, additional, and Crompton, Peter D, additional

Published
2017
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168. Investigation of HfO2-based resistive RAM cells by electrical characterization and atomistic simulations

Author

Traore, Boubacar, Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Université Grenoble Alpes, Barbara De Salvo, Elisa Vianello, and STAR, ABES

Subjects
Ab initio simulations atomistiques, Formation du filament conducteur, Conductive filament formation, Ab initio atomistic simulations, Diffusion migration des défauts, [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, HfOx suboxides, Diffusion migration of defects, Mémoire résistives RRAM, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, HfO2, Resistive memory RRAM, Sous oxides HfOx
Abstract

Among non-volatile memory technologies, NAND Flash represents a significant portion in the IC market and has benefitted from the traditional scaling of semiconductor industry allowing its high density integration. However, this scaling seems to be problematic beyond the 22 nm node. In an effort to go beyond this scaling limitation, alternative memory solutions are proposed among which Resistive RAM (RRAM) stands out as a serious candidate for NAND Flash replacement. Hence, in this PhD thesis we try to respond to many open questions about RRAM devices based on hafnium oxide (HfO2), in particular, by addressing the lack of detailed physical comprehension about their operation and reliability. The impact of scaling, the role of electrodes, the process of defects formation and diffusion are investigated. The impact of alloying/doping HfO2 with other materials for improved RRAM performance is also studied. Finally, our study attempts to provide some answers on the conductive filament formation, its stability and possible composition., La mémoire NAND Flash représente une part importante dans le marché des circuits intégrés et a bénéficié de la traditionnelle miniaturisation de l’industrie des sémiconducteurs lui permettant un niveau d’intégration élevé. Toutefois, cette miniaturisation semble poser des sérieux problèmes au-delà du noeud 22 nm. Dans un souci de dépasser cette limite, des solutions mémoires alternatives sont proposées parmi lesquelles la mémoire résistive (RRAM) se pose comme un sérieux candidat pour le remplacement de NAND Flash. Ainsi, dans cette thèse nous essayons de répondre à des nombreuses questions ouvertes sur les dispositifs RRAM à base d’oxyde d’hafnium (HfO2) en particulier en adressant le manque de compréhension physique détaillée sur leur fonctionnement et leur fiabilité. L’impact de la réduction de taille des RRAM, le rôle des électrodes et le processus de formation et de diffusion des défauts sont étudiés. L’impact de l’alliage/dopage de HfO2 avec d’autres matériaux pour l’optimisation des RRAM est aussi abordé. Enfin, notre étude tente de donner quelques réponses sur la formation du filament conducteur, sa stabilité et sa possible composition.

Published
2015

169. Increased circulation time of Plasmodium falciparumunderlies persistent asymptomatic infection in the dry season

Author

Andrade, Carolina M., Fleckenstein, Hannah, Thomson-Luque, Richard, Doumbo, Safiatou, Lima, Nathalia F., Anderson, Carrie, Hibbert, Julia, Hopp, Christine S., Tran, Tuan M., Li, Shanping, Niangaly, Moussa, Cisse, Hamidou, Doumtabe, Didier, Skinner, Jeff, Sturdevant, Dan, Ricklefs, Stacy, Virtaneva, Kimmo, Asghar, Muhammad, Homann, Manijeh Vafa, Turner, Louise, Martins, Joana, Allman, Erik L., N’Dri, Marie-Esther, Winkler, Volker, Llinás, Manuel, Lavazec, Catherine, Martens, Craig, Färnert, Anna, Kayentao, Kassoum, Ongoiba, Aissata, Lavstsen, Thomas, Osório, Nuno S., Otto, Thomas D., Recker, Mario, Traore, Boubacar, Crompton, Peter D., and Portugal, Silvia

Abstract

The dry season is a major challenge for Plasmodium falciparumparasites in many malaria endemic regions, where water availability limits mosquito vectors to only part of the year. How P. falciparumbridges two transmission seasons months apart, without being cleared by the human host or compromising host survival, is poorly understood. Here we show that low levels of P. falciparumparasites persist in the blood of asymptomatic Malian individuals during the 5- to 6-month dry season, rarely causing symptoms and minimally affecting the host immune response. Parasites isolated during the dry season are transcriptionally distinct from those of individuals with febrile malaria in the transmission season, coinciding with longer circulation within each replicative cycle of parasitized erythrocytes without adhering to the vascular endothelium. Low parasite levels during the dry season are not due to impaired replication but rather to increased splenic clearance of longer-circulating infected erythrocytes, which likely maintain parasitemias below clinical and immunological radar. We propose that P. falciparumvirulence in areas of seasonal malaria transmission is regulated so that the parasite decreases its endothelial binding capacity, allowing increased splenic clearance and enabling several months of subclinical parasite persistence.

Published
2020
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171. Advances and promises of layered halide hybrid perovskite semiconductors

Author

European Research Council, Agence Nationale de la Recherche (France), Ministerio de Economía y Competitividad (España), European Commission, Los Alamos National Laboratory, Fondation Banque Populaire de l'Ouest, Department of Energy (US), Foundation for Fundamental Research on Matter, Netherlands Organization for Scientific Research, Pedesseau, Laurent, Sapori, Daniel, Traore, Boubacar, Robles, Roberto, Fang, Hong-Hua, Loi, Maria Antonietta, Tsai, Hsinhan, Nie, Wanyi, Blancon, Jean-Christophe, Neukirch, Amanda, Tretiak, Sergei, Mohite, Ashwini A., Katan, Claudine, Even, Jacky, Kepenekian, M., European Research Council, Agence Nationale de la Recherche (France), Ministerio de Economía y Competitividad (España), European Commission, Los Alamos National Laboratory, Fondation Banque Populaire de l'Ouest, Department of Energy (US), Foundation for Fundamental Research on Matter, Netherlands Organization for Scientific Research, Pedesseau, Laurent, Sapori, Daniel, Traore, Boubacar, Robles, Roberto, Fang, Hong-Hua, Loi, Maria Antonietta, Tsai, Hsinhan, Nie, Wanyi, Blancon, Jean-Christophe, Neukirch, Amanda, Tretiak, Sergei, Mohite, Ashwini A., Katan, Claudine, Even, Jacky, and Kepenekian, M.

Abstract

Layered halide hybrid organic-inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells and revisited for light-emitting devices. In this review, we combine classical solid-state physics concepts with simulation tools based on density functional theory to overview the main features of the optoelectronic properties of layered HOP. A detailed comparison between layered and 3D HOP is performed to highlight differences and similarities. In the same way as the cubic phase was established for 3D HOP, here we introduce the tetragonal phase with D symmetry as the reference phase for 2D monolayered HOP. It allows for detailed analysis of the spin-orbit coupling effects and structural transitions with corresponding electronic band folding. We further investigate the effects of octahedral tilting on the band gap, loss of inversion symmetry and possible Rashba effect, quantum confinement, and dielectric confinement related to the organic barrier, up to excitonic properties. Altogether, this paper aims to provide an interpretive and predictive framework for 3D and 2D layered HOP optoelectronic properties.

Published
2016

172. Treatment of Chronic Asymptomatic Plasmodium falciparum Infection Does Not Increase the Risk of Clinical Malaria Upon Reinfection

Author

Portugal, Silvia, primary, Tran, Tuan M., additional, Ongoiba, Aissata, additional, Bathily, Aboudramane, additional, Li, Shanping, additional, Doumbo, Safiatou, additional, Skinner, Jeff, additional, Doumtabe, Didier, additional, Kone, Younoussou, additional, Sangala, Jules, additional, Jain, Aarti, additional, Davies, D. Huw, additional, Hung, Christopher, additional, Liang, Li, additional, Ricklefs, Stacy, additional, Homann, Manijeh Vafa, additional, Felgner, Philip L., additional, Porcella, Stephen F., additional, Färnert, Anna, additional, Doumbo, Ogobara K., additional, Kayentao, Kassoum, additional, Greenwood, Brian M., additional, Traore, Boubacar, additional, and Crompton, Peter D., additional

Published
2016
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173. The Regulation of Inherently Autoreactive VH4-34–Expressing B Cells in Individuals Living in a Malaria-Endemic Area of West Africa

Author

Hart, Geoffrey T., primary, Akkaya, Munir, additional, Chida, Asiya S., additional, Wei, Chungwen, additional, Jenks, Scott A., additional, Tipton, Christopher, additional, He, Chenfeng, additional, Wendel, Ben S., additional, Skinner, Jeff, additional, Arora, Gunjan, additional, Kayentao, Kassoum, additional, Ongoiba, Aissata, additional, Doumbo, Ogobara, additional, Traore, Boubacar, additional, Narum, David L., additional, Jiang, Ning, additional, Crompton, Peter D., additional, Sanz, Ignacio, additional, and Pierce, Susan K., additional

Published
2016
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174. Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors

Author

Pedesseau, Laurent, primary, Sapori, Daniel, additional, Traore, Boubacar, additional, Robles, Roberto, additional, Fang, Hong-Hua, additional, Loi, Maria Antonietta, additional, Tsai, Hsinhan, additional, Nie, Wanyi, additional, Blancon, Jean-Christophe, additional, Neukirch, Amanda, additional, Tretiak, Sergei, additional, Mohite, Aditya D., additional, Katan, Claudine, additional, Even, Jacky, additional, and Kepenekian, Mikaël, additional

Published
2016
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175. Transcriptomic evidence for modulation of host inflammatory responses during febrile Plasmodium falciparum malaria

Author

Tran, Tuan M., primary, Jones, Marcus B., additional, Ongoiba, Aissata, additional, Bijker, Else M., additional, Schats, Remko, additional, Venepally, Pratap, additional, Skinner, Jeff, additional, Doumbo, Safiatou, additional, Quinten, Edwin, additional, Visser, Leo G., additional, Whalen, Elizabeth, additional, Presnell, Scott, additional, O’Connell, Elise M., additional, Kayentao, Kassoum, additional, Doumbo, Ogobara K., additional, Chaussabel, Damien, additional, Lorenzi, Hernan, additional, Nutman, Thomas B., additional, Ottenhoff, Tom H. M., additional, Haks, Mariëlle C., additional, Traore, Boubacar, additional, Kirkness, Ewen F., additional, Sauerwein, Robert W., additional, and Crompton, Peter D., additional

Published
2016
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176. Investigation of Cycle-to-Cycle Variability in HfO2-Based OxRAM

Author

Piccolboni, Giuseppe, primary, Molas, Gabriel, additional, Garbin, Daniele, additional, Vianello, Elisa, additional, Cueto, Olga, additional, Cagli, Carlo, additional, Traore, Boubacar, additional, De Salvo, Barbara, additional, Ghibaudo, Gerard, additional, and Perniola, Luca, additional

Published
2016
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177. Does Rashba splitting in CH3NH3PbBr3 arise from 2 × 2 surface reconstruction?

Author

Che, Xiaoyang, Traore, Boubacar, Katan, Claudine, Kepenekian, Mikaël, and Even, Jacky

Abstract

As a result of early theoretical predictions, evidence for the Rashba or Dresselhaus effect in hybrid perovskites has recently attracted several experimental investigations, motivated by possible applications in spin-orbitronics. For instance, a large Rashba splitting has recently been reported for the (001) surface of CH3NH3PbBr3. This effect is forbidden in the bulk material since both low-temperature and room-temperature crystal structures present inversion symmetry. Here we investigate the effects of two (001) nanoscale surface reconstructions of CH3NH3PbBr3 using first-principles approaches based on density functional theory (DFT). The two experimental reconstructions are related to different orientations of MA cations at the surface, defining zigzag and dimer phases. The impact of these structural transformations on their electronic structures is thoroughly investigated. Whereas calculations reveal the occurrence of surface-induced Rashba effect, its amplitude is considerably smaller than the experimentally reported value, in agreement with other experimental investigations and leading to the conclusion that mesoscale surface polar domains and/or surface defects may result from sample preparation. [ABSTRACT FROM AUTHOR]

Published
2018
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179. HfO2/Ti Interface Mediated Conductive Filament Formation in RRAM: An Ab Initio Study.

Author

Blaise, Philippe, Sklénard, Benoît, Vianello, Elisa, Traore, Boubacar, Magyari-Köpe, Blanka, and Yoshio Nishi

Subjects
INTERFACE circuits, RECORDS management, FIBERS, RANDOM access memory, DIFFUSION, EXPERIMENTS
Abstract

We address the role of the Ti/HfO2 interface on the conductive filament (CF) formation within the context of oxide-based resistive random access memories (OxRRAMs). We investigate oxygen defects formation and diffusion at the interface through ab initio calculations. The calculated diffusion energy barriers compare well with the available experimental data. Through the interface region charge analysis and the associated energies with O defect formation and migration into Ti, our results support a probable CF growth from the interface region toward the electroninjectingelectrode,which acts as a cathode.Hence, for a Ti/HfO2-based OxRRAM supported by the calculation results, we present a pertinent CF growth model by considering its earliest stages, which is relevant for device modeling. [ABSTRACT FROM AUTHOR]

Published
2018
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180. Analysis of the B cell responsiveness to the TLR9 agonist CPG in malaria semi-immune versus malaria na�ve individuals

Author

Ongoiba Aissata, K Doumbo Ogobara, Kone Younoussou, K Pierce Susan, D Crompton Peter, Doumtabe Didier, Traore Boubacar, Kayentao Kassoum, Moebius Jacqueline, Niare Doumbo Safiatou, and Portugal Silvia

Subjects
Agonist, medicine.drug_class, business.industry, Immunology, TLR9, medicine.disease, Immune system, medicine.anatomical_structure, CpG site, medicine, Immunology and Allergy, business, B cell, Malaria
Published
2013
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181. Advances and Promises of Layered Halide Hybrid Perovskite Semiconductors

Author

Pedesseau, Laurent, Sapori, Daniel, Traore, Boubacar, Robles, Roberto, Fang, Hong-Hua, Loi, Maria Antonietta, Tsai, Hsinhan, Nie, Wanyi, Blancon, Jean-Christophe, Neukirch, Amanda, Tretiak, Sergei, Mohite, Aditya D., Katan, Claudine, Even, Jacky, and Kepenekian, Mikaël

Abstract

Layered halide hybrid organic–inorganic perovskites (HOP) have been the subject of intense investigation before the rise of three-dimensional (3D) HOP and their impressive performance in solar cells. Recently, layered HOP have also been proposed as attractive alternatives for photostable solar cells and revisited for light-emitting devices. In this review, we combine classical solid-state physics concepts with simulation tools based on density functional theory to overview the main features of the optoelectronic properties of layered HOP. A detailed comparison between layered and 3D HOP is performed to highlight differences and similarities. In the same way as the cubic phase was established for 3D HOP, here we introduce the tetragonal phase with D4hsymmetry as the reference phase for 2D monolayered HOP. It allows for detailed analysis of the spin–orbit coupling effects and structural transitions with corresponding electronic band folding. We further investigate the effects of octahedral tilting on the band gap, loss of inversion symmetry and possible Rashba effect, quantum confinement, and dielectric confinement related to the organic barrier, up to excitonic properties. Altogether, this paper aims to provide an interpretive and predictive framework for 3D and 2D layered HOP optoelectronic properties.

Published
2024
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183. Genetic Resistance to Malaria Is Associated With Greater Enhancement of Immunoglobulin (Ig)M Than IgG Responses to a Broad Array of Plasmodium falciparum Antigens

Author

Arama, Charles, Skinner, Jeff, Doumtabe, Didier, Portugal, Silvia, Tran, Tuan M., Jain, Aarti, Traore, Boubacar, Doumbo, Ogobara K., Davies, David Huw, Troye-Blomberg, Marita, Dolo, Amagana, Felgner, Philip L., Crompton, Peter D., Arama, Charles, Skinner, Jeff, Doumtabe, Didier, Portugal, Silvia, Tran, Tuan M., Jain, Aarti, Traore, Boubacar, Doumbo, Ogobara K., Davies, David Huw, Troye-Blomberg, Marita, Dolo, Amagana, Felgner, Philip L., and Crompton, Peter D.

Abstract

Background. People of the Fulani ethnic group are more resistant to malaria compared with genetically distinct ethnic groups, such as the Dogon people, in West Africa, and studies suggest that this resistance is mediated by enhanced antibody responses to Plasmodium falciparum antigens. However, prior studies measured antibody responses to < 0.1% of P falciparum proteins, so whether the Fulani mount an enhanced and broadly reactive immunoglobulin (Ig) M and IgG response to P falciparum remains unknown. In general, little is known about the extent to which host genetics influence the overall antigen specificity of IgM and IgG responses to natural infections. Methods. In a cross-sectional study in Mali, we collected plasma from asymptomatic, age-matched Fulani (n = 24) and Dogon (n = 22) adults with or without concurrent P falciparum infection. We probed plasma against a protein microarray containing 1087 P falciparum antigens and compared IgM and IgG profiles by ethnicity. Results. We found that the breadth and magnitude of P falciparum-specific IgM and IgG responses were significantly higher in the malaria-resistant Fulani versus the malaria-susceptible Dogon, and, unexpectedly, P falciparum-specific IgM responses more strongly distinguished the 2 ethnic groups. Conclusions. These findings point to an underappreciated role for IgM in protection from malaria, and they suggest that host genetics may influence the antigen specificity of IgM and IgG responses to infection.

Published
2015
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185. Stool microbiota composition is associated with the prospective risk of Plasmodium falciparum infection

Author

Yooseph, Shibu, primary, Kirkness, Ewen F., additional, Tran, Tuan M., additional, Harkins, Derek M., additional, Jones, Marcus B., additional, Torralba, Manolito G., additional, O’Connell, Elise, additional, Nutman, Thomas B., additional, Doumbo, Safiatou, additional, Doumbo, Ogobara K., additional, Traore, Boubacar, additional, Crompton, Peter D., additional, and Nelson, Karen E., additional

Published
2015
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186. Malaria-associated atypical memory B cells exhibit markedly reduced B cell receptor signaling and effector function

Author

Portugal, Silvia, primary, Tipton, Christopher M, additional, Sohn, Haewon, additional, Kone, Younoussou, additional, Wang, Jing, additional, Li, Shanping, additional, Skinner, Jeff, additional, Virtaneva, Kimmo, additional, Sturdevant, Daniel E, additional, Porcella, Stephen F, additional, Doumbo, Ogobara K, additional, Doumbo, Safiatou, additional, Kayentao, Kassoum, additional, Ongoiba, Aissata, additional, Traore, Boubacar, additional, Sanz, Inaki, additional, Pierce, Susan K, additional, and Crompton, Peter D, additional

Published
2015
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188. Author response: Malaria-associated atypical memory B cells exhibit markedly reduced B cell receptor signaling and effector function

Author

Portugal, Silvia, primary, Tipton, Christopher M, additional, Sohn, Haewon, additional, Kone, Younoussou, additional, Wang, Jing, additional, Li, Shanping, additional, Skinner, Jeff, additional, Virtaneva, Kimmo, additional, Sturdevant, Daniel E, additional, Porcella, Stephen F, additional, Doumbo, Ogobara K, additional, Doumbo, Safiatou, additional, Kayentao, Kassoum, additional, Ongoiba, Aissata, additional, Traore, Boubacar, additional, Sanz, Inaki, additional, Pierce, Susan K, additional, and Crompton, Peter D, additional

Published
2015
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189. Malaria-induced interferon-γ drives the expansion of Tbethi atypical memory B cells.

Author

Obeng-Adjei, Nyamekye, Portugal, Silvia, Holla, Prasida, Li, Shanping, Sohn, Haewon, Ambegaonkar, Abhijit, Skinner, Jeff, Bowyer, Georgina, Doumbo, Ogobara K., Traore, Boubacar, Pierce, Susan K., and Crompton, Peter D.

Subjects
MALARIA, INTERFERON gamma, B cells, GENE expression, T helper cells, IMMUNE system
Abstract

Many chronic infections, including malaria and HIV, are associated with a large expansion of CD21−CD27− ‘atypical’ memory B cells (MBCs) that exhibit reduced B cell receptor (BCR) signaling and effector functions. Little is known about the conditions or transcriptional regulators driving atypical MBC differentiation. Here we show that atypical MBCs in malaria-exposed individuals highly express the transcription factor T-bet, and that T-bet expression correlates inversely with BCR signaling and skews toward IgG3 class switching. Moreover, a longitudinal analysis of a subset of children suggested a correlation between the incidence of febrile malaria and the expansion of T-bethi B cells. The Th1-cytokine containing supernatants of malaria-stimulated PBMCs plus BCR cross linking induced T-bet expression in naïve B cells that was abrogated by neutralizing IFN-γ or blocking the IFN-γ receptor on B cells. Accordingly, recombinant IFN-γ plus BCR cross-linking drove T-bet expression in peripheral and tonsillar B cells. Consistent with this, Th1-polarized Tfh (Tfh-1) cells more efficiently induced T-bet expression in naïve B cells. These data provide new insight into the mechanisms underlying atypical MBC differentiation. [ABSTRACT FROM AUTHOR]

Published
2017
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191. Genetic Resistance to Malaria Is Associated With Greater Enhancement of Immunoglobulin (Ig)M Than IgG Responses to a Broad Array of Plasmodium falciparum Antigens

Author

Arama, Charles, primary, Skinner, Jeff, additional, Doumtabe, Didier, additional, Portugal, Silvia, additional, Tran, Tuan M., additional, Jain, Aarti, additional, Traore, Boubacar, additional, Doumbo, Ogobara K., additional, Davies, David Huw, additional, Troye-Blomberg, Marita, additional, Dolo, Amagana, additional, Felgner, Philip L., additional, and Crompton, Peter D., additional

Published
2015
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192. Investigating the Longevity of Plasmodium falciparum-Specific Immunoglobulin G Responses in Absence of Infection: A Longitudinal Study in Mali

Author

Liu, Eugene, primary, -Yu Huang, AQ, additional, Skinner, Jeff, additional, Jain, Aarti, additional, Ongoiba, Aissata, additional, Li, Shanping, additional, Doumbo, Safiatou, additional, Doumtabe, Didier, additional, Kone, Younoussou, additional, Bathily, Aboudramane, additional, Sangala, Jules, additional, Doumbo, Ogobara K., additional, Kayentao, Kassoum, additional, Traore, Boubacar, additional, Felgner, Philip, additional, and Crompton, Peter D., additional

Published
2015
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193. Parasite clearance following treatment with sulphadoxine-pyrimethamine for intermittent preventive treatment in Burkina-Faso and Mali:42-day in vivo follow-up study

Author

Coulibaly, Sheick O, Kayentao, Kassoum, Taylor, Steve, Guirou, Etienne A, Khairallah, Carole, Guindo, Nouhoun, Djimde, Moussa, Bationo, Richard, Soulama, Alamissa, Dabira, Edgar, Barry, Binta, Niangaly, Moussa, Diakite, Hammadoun, Konate, Sidiki, Keita, Mohamed, Traore, Boubacar, Meshnick, Steve R, Magnussen, Pascal, Doumbo, Ogobara K, Ter Kuile, Feiko O, Coulibaly, Sheick O, Kayentao, Kassoum, Taylor, Steve, Guirou, Etienne A, Khairallah, Carole, Guindo, Nouhoun, Djimde, Moussa, Bationo, Richard, Soulama, Alamissa, Dabira, Edgar, Barry, Binta, Niangaly, Moussa, Diakite, Hammadoun, Konate, Sidiki, Keita, Mohamed, Traore, Boubacar, Meshnick, Steve R, Magnussen, Pascal, Doumbo, Ogobara K, and Ter Kuile, Feiko O

Abstract

Intermittent Preventive Treatment in pregnancy (IPTp) with sulphadoxine-pyrimethamine (SP) is widely used for the control of malaria in pregnancy in Africa. The emergence of resistance to SP is a concern requiring monitoring the effectiveness of SP for IPTp.

Published
2014

195. Exposure-Dependent Control of Malaria-Induced Inflammation in Children

Author

Portugal, Silvia, primary, Moebius, Jacqueline, additional, Skinner, Jeff, additional, Doumbo, Safiatou, additional, Doumtabe, Didier, additional, Kone, Younoussou, additional, Dia, Seydou, additional, Kanakabandi, Kishore, additional, Sturdevant, Daniel E., additional, Virtaneva, Kimmo, additional, Porcella, Stephen F., additional, Li, Shanping, additional, Doumbo, Ogobara K., additional, Kayentao, Kassoum, additional, Ongoiba, Aissata, additional, Traore, Boubacar, additional, and Crompton, Peter D., additional

Published
2014
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196. An intensive longitudinal cohort study of Malian children and adults reveals no evidence of acquired immunity to Plasmodium falciparum infection.

Author

Tran, Tuan, Tran, Tuan, Li, Shanping, Doumbo, Safiatou, Doumtabe, Didier, Huang, Chiung-Yu, Dia, Seydou, Bathily, Aboudramane, Sangala, Jules, Kone, Younoussou, Traore, Abdrahamane, Niangaly, Moussa, Dara, Charles, Kayentao, Kassoum, Ongoiba, Aissata, Doumbo, Ogobara, Traore, Boubacar, Crompton, Peter, Tran, Tuan, Tran, Tuan, Li, Shanping, Doumbo, Safiatou, Doumtabe, Didier, Huang, Chiung-Yu, Dia, Seydou, Bathily, Aboudramane, Sangala, Jules, Kone, Younoussou, Traore, Abdrahamane, Niangaly, Moussa, Dara, Charles, Kayentao, Kassoum, Ongoiba, Aissata, Doumbo, Ogobara, Traore, Boubacar, and Crompton, Peter

Abstract

BACKGROUND: In experimental models of human and mouse malaria, sterilizing liver stage immunity that blocks progression of Plasmodium infection to the symptomatic blood stage can be readily demonstrated. However, it remains unclear whether individuals in malaria-endemic areas acquire such immunity. METHODS: In Mali, 251 healthy children and adults aged 4-25 years who were free of blood-stage Plasmodium infection by polymerase chain reaction (PCR) were enrolled in a longitudinal study just prior to an intense 6-month malaria season. Subsequent clinical malaria episodes were detected by weekly active surveillance and self-referral. Asymptomatic P. falciparum infections were detected by blood-smear microscopy and PCR analysis of dried blood spots that had been collected every 2 weeks for 7 months. RESULTS: As expected, the risk of clinical malaria decreased with increasing age (log-rank test, P = .0038). However, analysis of PCR data showed no age-related differences in P. falciparum infection risk (log-rank test, P = .37). CONCLUSIONS: Despite years of exposure to intense P. falciparum transmission, there is no evidence of acquired, sterile immunity to P. falciparum infection in this population, even as clinical immunity to blood-stage malaria is clearly acquired. Understanding why repeated P. falciparum infections do not induce sterile protection may lead to insights for developing vaccines that target the liver stage in malaria-endemic populations.

Published
2013

197. Changes in the levels of cytokines, chemokines and malaria specific antibodies in response to Plasmodium falciparum infection in children living in sympatry in Mali

Author

Boström, Stephanie, Giusti, Pablo, Arama, Charles, Persson, Jan-Olov, Dara, Victor, Traore, Boubacar, Dolo, Amagana, Doumbo, Ogobara, Troye-Blomberg, Marita, Boström, Stephanie, Giusti, Pablo, Arama, Charles, Persson, Jan-Olov, Dara, Victor, Traore, Boubacar, Dolo, Amagana, Doumbo, Ogobara, and Troye-Blomberg, Marita

Abstract

Background: The Fulani are known to be less susceptible to Plasmodium falciparum malaria as reflected by lower parasitaemia and fewer clinical symptoms than other sympatric ethnic groups. So far most studies in these groups have been performed on adults, which is why little is known about these responses in children. This study was designed to provide more information on this gap. Methods: Circulating inflammatory factors and antibody levels in children from the Fulani and Dogon ethnic groups were measured. The inflammatory cytokines; interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12p70, tumor necrosis factor (TNF) and the chemokines; regulated on activation normal T cell expressed and secreted (RANTES), monokine-induced by IFN-gamma (MIG), monocyte chemotactic protein (MCP)-1 and IFN-gamma-inducible protein (IP)-10 were measured by cytometric bead arrays. The levels of interferon (IFN)-alpha, IFN-gamma and malaria-specific antibodies; immunoglobulin (Ig) G, IgM and IgG subclasses (IgG1-IgG4) were measured by ELISA. Results: The results revealed that the Fulani children had higher levels of all tested cytokines compared to the Dogon, in particular IFN-gamma, a cytokine known to be involved in parasite clearance. Out of all the tested chemokines, only MCP-1 was increased in the Fulani compared to the Dogon. When dividing the children into infected and uninfected individuals, infected Dogon had significantly lower levels of RANTES compared to their uninfected peers, and significantly higher levels of MIG and IP-10 as well as MCP-1, although the latter did not reach statistical significance. In contrast, such patterns were not seen in the infected Fulani children and their chemokine levels remained unchanged upon infection compared to uninfected counterparts. Furthermore, the Fulani also had higher titres of malaria-specific IgG and IgM as well as IgG1-3 subclasses compared to the Dogon. Conclusions: Taken together, this study demonstrates, in accordance with previous w, AuthorCount:9

Published
2012
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198. B cell analysis of ethnic groups in Mali with differential susceptibility to malaria

Author

Portugal, Silvia, Doumtabe, Didier, Traore, Boubacar, Miller, Louis H., Troye-Blomberg, Marita, Doumbo, Ogobara K., Dolo, Amagana, Pierce, Susan K., Crompton, Peter D., Portugal, Silvia, Doumtabe, Didier, Traore, Boubacar, Miller, Louis H., Troye-Blomberg, Marita, Doumbo, Ogobara K., Dolo, Amagana, Pierce, Susan K., and Crompton, Peter D.

Abstract

Background: Several studies indicate that people of the Fulani ethnic group are less susceptible to malaria compared to those of other ethnic groups living sympatrically in Africa, including the Dogon ethnic group. Although the mechanisms of this protection remain unclear, the Fulani are known to have higher levels of Plasmodium falciparum-specific antibodies of all Ig classes as compared to the Dogon. However, the proportions of B cell subsets in the Fulani and Dogon that may account for differences in the levels of Ig have not been characterized. Methods: In this cross-sectional study, venous blood was collected from asymptomatic Fulani (n = 25) and Dogon (n = 25) adults in Mali during the malaria season, and from P. falciparum-naive adults in the U. S. (n = 8). At the time of the blood collection, P. falciparum infection was detected by blood-smear in 16% of the Fulani and 36% of the Dogon volunteers. Thawed lymphocytes were analysed by flow cytometry to quantify B cell subsets, including immature and naive B cells; plasma cells; and classical, activated, and atypical memory B cells (MBCs). Results: The overall distribution of B cell subsets was similar between Fulani and Dogon adults, although the percentage of activated MBCs was higher in the Fulani group (Fulani: 11.07% [95% CI: 9.317 - 12.82]; Dogon: 8.31% [95% CI: 6.378 - 10.23]; P = 0.016). The percentage of atypical MBCs was similar between Fulani and Dogon adults (Fulani: 28.3% [95% CI: 22.73 - 34.88]; Dogon: 29.3% [95% CI: 25.06 - 33.55], but higher than U. S. adults (U. S.: 3.0% [95% CI: -0.21 - 6.164]; P < 0.001). Plasmodium falciparum infection was associated with a higher percentage of plasma cells among Fulani (Fulani infected: 3.3% [95% CI: 1.788 - 4.744]; Fulani uninfected: 1.71% [95% CI: 1.33 - 2.08]; P = 0.011), but not Dogon adults. Conclusion: These data show that the malaria-resistant Fulani have a higher percentage of activated MBCs compared to the Dogon, and that P. falciparum infection, AuthorCount:9

Published
2012
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200. Parasite clearance following treatment with sulphadoxine-pyrimethamine for intermittent preventive treatment in Burkina-Faso and Mali: 42-day in vivo follow-up study

Author

Coulibaly, Sheick O, primary, Kayentao, Kassoum, additional, Taylor, Steve, additional, Guirou, Etienne A, additional, Khairallah, Carole, additional, Guindo, Nouhoun, additional, Djimde, Moussa, additional, Bationo, Richard, additional, Soulama, Alamissa, additional, Dabira, Edgar, additional, Barry, Binta, additional, Niangaly, Moussa, additional, Diakite, Hammadoun, additional, Konate, Sidiki, additional, Keita, Mohamed, additional, Traore, Boubacar, additional, Meshnick, Steve R, additional, Magnussen, Pascal, additional, Doumbo, Ogobara K, additional, and ter Kuile, Feiko O, additional

Published
2014
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