TY  - JOUR
A1  - Warrington, Nicole
A1  - Beaumont, Robin
A1  - Horikoshi, Momoko
A1  - Day, Felix R.
A1  - Helgeland, Øyvind
A1  - Laurin, Charles
A1  - Bacelis, Jonas
A1  - Peng, Shouneng
A1  - Hao, Ke
A1  - Feenstra, Bjarke
A1  - Wood, Andrew R.
A1  - Mahajan, Anubha
A1  - Tyrrell, Jessica
A1  - Robertson, Neil R.
A1  - Rayner, N. William
A1  - Qiao, Zhen
A1  - Moen, Gunn-Helen
A1  - Vaudel, Marc
A1  - Marsit, Carmen
A1  - Chen, Jia
A1  - Nodzenski, Michael
A1  - Schnurr, Theresia M.
A1  - Zafarmand, Mohammad Hadi
A1  - Bradfield, Jonathan P.
A1  - Grarup, Niels
A1  - Kooijman, Marjolein N.
A1  - Li-Gao, Ruifang
A1  - Geller, Frank
A1  - Ahluwalia, Tarunveer Singh
A1  - Paternoster, Lavinia
A1  - Rueedi, Rico
A1  - Huikari, Ville
A1  - Hottenga, Jouke-Jan
A1  - Lyytikäinen, Leo-Pekka
A1  - Cavadino, Alana
A1  - Metrustry, Sarah
A1  - Cousminer, Diana L.
A1  - Wu, Ying
A1  - Thiering, Elisabeth Paula
A1  - Wang, Carol A.
A1  - Have, Christian Theil
A1  - Vilor-Tejedor, Natalia
A1  - Joshi, Peter K.
A1  - Painter, Jodie N.
A1  - Ntalla, Ioanna
A1  - Myhre, Ronny
A1  - Pitkänen, Niina
A1  - van Leeuwen, Elisabeth M.
A1  - Joro, Raimo
A1  - Lagou, Vasiliki
A1  - Richmond, Rebecca C.
A1  - Espinosa, Ana
A1  - Barton, Sheila J.
A1  - Inskip, Hazel M.
A1  - Holloway, John W.
A1  - Santa-Marina, Loreto
A1  - Estivill, Xavier
A1  - Ang, Wei
A1  - Marsh, Julie A.
A1  - Reichetzeder, Christoph
A1  - Marullo, Letizia
A1  - Hocher, Berthold
A1  - Lunetta, Kathryn L.
A1  - Murabito, Joanne M.
A1  - Relton, Caroline L.
A1  - Kogevinas, Manolis
A1  - Chatzi, Leda
A1  - Allard, Catherine
A1  - Bouchard, Luigi
A1  - Hivert, Marie-France
A1  - Zhang, Ge
A1  - Muglia, Louis J.
A1  - Heikkinen, Jani
A1  - Morgen, Camilla S.
A1  - van Kampen, Antoine H. C.
A1  - van Schaik, Barbera D. C.
A1  - Mentch, Frank D.
A1  - Langenberg, Claudia
A1  - Scott, Robert A.
A1  - Zhao, Jing Hua
A1  - Hemani, Gibran
A1  - Ring, Susan M.
A1  - Bennett, Amanda J.
A1  - Gaulton, Kyle J.
A1  - Fernandez-Tajes, Juan
A1  - van Zuydam, Natalie R.
A1  - Medina-Gomez, Carolina
A1  - de Haan, Hugoline G.
A1  - Rosendaal, Frits R.
A1  - Kutalik, Zoltán
A1  - Marques-Vidal, Pedro
A1  - Das, Shikta
A1  - Willemsen, Gonneke
A1  - Mbarek, Hamdi
A1  - Müller-Nurasyid, Martina
A1  - Standl, Marie
A1  - Appel, Emil V. R.
A1  - Fonvig, Cilius Esmann
A1  - Trier, Caecilie
A1  - van Beijsterveldt, Catharina E. M.
A1  - Murcia, Mario
A1  - Bustamante, Mariona
A1  - Bonàs-Guarch, Sílvia
A1  - Hougaard, David M.
A1  - Mercader, Josep M.
A1  - Linneberg, Allan
A1  - Schraut, Katharina E.
A1  - Lind, Penelope A.
A1  - Medland, Sarah Elizabeth
A1  - Shields, Beverley M.
A1  - Knight, Bridget A.
A1  - Chai, Jin-Fang
A1  - Panoutsopoulou, Kalliope
A1  - Bartels, Meike
A1  - Sánchez, Friman
A1  - Stokholm, Jakob
A1  - Torrents, David
A1  - Vinding, Rebecca K.
A1  - Willems, Sara M.
A1  - Atalay, Mustafa
A1  - Chawes, Bo L.
A1  - Kovacs, Peter
A1  - Prokopenko, Inga
A1  - Tuke, Marcus A.
A1  - Yaghootkar, Hanieh
A1  - Ruth, Katherine S.
A1  - Jones, Samuel E.
A1  - Loh, Po-Ru
A1  - Murray, Anna
A1  - Weedon, Michael N.
A1  - Tönjes, Anke
A1  - Stumvoll, Michael
A1  - Michaelsen, Kim Fleischer
A1  - Eloranta, Aino-Maija
A1  - Lakka, Timo A.
A1  - van Duijn, Cornelia M.
A1  - Kiess, Wieland
A1  - Koerner, Antje
A1  - Niinikoski, Harri
A1  - Pahkala, Katja
A1  - Raitakari, Olli T.
A1  - Jacobsson, Bo
A1  - Zeggini, Eleftheria
A1  - Dedoussis, George V.
A1  - Teo, Yik-Ying
A1  - Saw, Seang-Mei
A1  - Montgomery, Grant W.
A1  - Campbell, Harry
A1  - Wilson, James F.
A1  - Vrijkotte, Tanja G. M.
A1  - Vrijheid, Martine
A1  - de Geus, Eco J. C. N.
A1  - Hayes, M. Geoffrey
A1  - Kadarmideen, Haja N.
A1  - Holm, Jens-Christian
A1  - Beilin, Lawrence J.
A1  - Pennell, Craig E.
A1  - Heinrich, Joachim
A1  - Adair, Linda S.
A1  - Borja, Judith B.
A1  - Mohlke, Karen L.
A1  - Eriksson, Johan G.
A1  - Widen, Elisabeth E.
A1  - Hattersley, Andrew T.
A1  - Spector, Tim D.
A1  - Kaehoenen, Mika
A1  - Viikari, Jorma S.
A1  - Lehtimaeki, Terho
A1  - Boomsma, Dorret I.
A1  - Sebert, Sylvain
A1  - Vollenweider, Peter
A1  - Sorensen, Thorkild I. A.
A1  - Bisgaard, Hans
A1  - Bonnelykke, Klaus
A1  - Murray, Jeffrey C.
A1  - Melbye, Mads
A1  - Nohr, Ellen A.
A1  - Mook-Kanamori, Dennis O.
A1  - Rivadeneira, Fernando
A1  - Hofman, Albert
A1  - Felix, Janine F.
A1  - Jaddoe, Vincent W. V.
A1  - Hansen, Torben
A1  - Pisinger, Charlotta
A1  - Vaag, Allan A.
A1  - Pedersen, Oluf
A1  - Uitterlinden, Andre G.
A1  - Jarvelin, Marjo-Riitta
A1  - Power, Christine
A1  - Hypponen, Elina
A1  - Scholtens, Denise M.
A1  - Lowe, William L.
A1  - Smith, George Davey
A1  - Timpson, Nicholas J.
A1  - Morris, Andrew P.
A1  - Wareham, Nicholas J.
A1  - Hakonarson, Hakon
A1  - Grant, Struan F. A.
A1  - Frayling, Timothy M.
A1  - Lawlor, Debbie A.
A1  - Njolstad, Pal R.
A1  - Johansson, Stefan
A1  - Ong, Ken K.
A1  - McCarthy, Mark I.
A1  - Perry, John R. B.
A1  - Evans, David M.
A1  - Freathy, Rachel M.
T1  - Maternal and fetal genetic effects on birth weight and their relevance to cardio-metabolic risk factors
JF  - Nature genetics
N2  - Birth weight variation is influenced by fetal and maternal genetic and non-genetic factors, and has been reproducibly associated with future cardio-metabolic health outcomes. In expanded genome-wide association analyses of own birth weight (n = 321,223) and offspring birth weight (n = 230,069 mothers), we identified 190 independent association signals (129 of which are novel). We used structural equation modeling to decompose the contributions of direct fetal and indirect maternal genetic effects, then applied Mendelian randomization to illuminate causal pathways. For example, both indirect maternal and direct fetal genetic effects drive the observational relationship between lower birth weight and higher later blood pressure: maternal blood pressure-raising alleles reduce offspring birth weight, but only direct fetal effects of these alleles, once inherited, increase later offspring blood pressure. Using maternal birth weight-lowering genotypes to proxy for an adverse intrauterine environment provided no evidence that it causally raises offspring blood pressure, indicating that the inverse birth weight-blood pressure association is attributable to genetic effects, and not to intrauterine programming.
Y1  - 2019
SN  - 1061-4036
SN  - 1546-1718
VL  - 51
IS  - 5
SP  - 804
EP  - +
PB  - Nature Publ. Group
CY  - New York
ER  - 
TY  - JOUR
A1  - Huang, Wentao
A1  - Jackson, Michael J.
A1  - Dekkers, Mark J.
A1  - Zhang, Yang
A1  - Zhang, Bo
A1  - Guo, Zhaojie
A1  - Dupont-Nivet, Guillaume
T1  - Challenges in isolating primary remanent magnetization from Tethyan carbonate rocks on the Tibetan Plateau: Insight from remagnetized Upper Triassic limestones in the eastern Qiangtang block
JF  - Earth & planetary science letters
N2  - Carbonate rocks, widely used for paleomagnetically quantifying the drift history of the Gondwana derived continental blocks of the Tibetan Plateau and evolution of the Paleo/Meso/Neo-Tethys Oceans, are prone to pervasive remagnetization. Identifying remagnetization is difficult because it is commonly undetectable through the classic paleomagnetic field tests. Here we apply comprehensive paleomagnetic, rock magnetic, and petrographic studies to upper Triassic limestones in the eastern Qiangtang block. Our results reveal that detrital/biogenic magnetite, which may carry the primary natural remanent magnetization (NRM), is rarely preserved in these rocks. In contrast, authigenic magnetite and hematite pseudomorphs after pyrite, and monoclinic pyrrhotite record three episodes of remagnetization. The earliest remagnetization was induced by oxidation of early diagenetic pyrite to magnetite, probably related to the collision between the northeastern Tibetan Plateau and the Qiangtang block after closure of the Paleo-Tethys Ocean in the Late Triassic. The second remagnetization, residing in hematite and minor goethite, which is the further subsurface oxidation product of pyrite/magnetite, is possibly related to the development of the localized Cenozoic basins soon after India-Asia collision in the Paleocene. The youngest remagnetization is a combination of thermoviscous and chemical remanent magnetization carried by authigenic magnetite and pyrrhotite, respectively. Our analyses suggest that a high supply of organic carbon during carbonate deposition, prevailing sulfate reducing conditions during early diagenesis, and widespread orogenic fluid migration related to crustal shortening during later diagenesis, have altered the primary remanence of the shallow-water Tethyan carbonate rocks of the Tibetan Plateau. We emphasize that all paleomagnetic results from these rocks must be carefully examined for remagnetization before being used for paleogeographic reconstructions. Future paleomagnetic investigations of the carbonate rocks in orogenic belts should be accompanied by thorough rock magnetic and petrographic studies to determine the origin of the NRM. (C) 2019 Elsevier B.V. All rights reserved.
KW  - Triassic limestone
KW  - remagnetization
KW  - Tibetan Plateau
Y1  - 2019
U6  - https://doi.org/10.1016/j.epsl.2019.06.035
SN  - 0012-821X
SN  - 1385-013X
VL  - 523
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Chen, Shun-Gang
A1  - Li, Ji
A1  - Zhang, Fan
A1  - Xiao, Bo
A1  - Hu, Jia-Ming
A1  - Cui, Yin-Qiu
A1  - Hofreiter, Michael
A1  - Hou, Xin-Dong
A1  - Sheng, Gui-Lian
A1  - Lai, Xu-Long
A1  - Yuan, Jun-Xia
T1  - Different maternal lineages revealed by ancient mitochondrial genome of Camelus bactrianus from China
JF  - Mitochondrial DNA Part A
N2  - Domestic Bactrian camel (Camelus bactrianus) used to be one of the most important livestock species in Chinese history, as well as the major transport carrier on the ancient Silk Road. However, archeological studies on Chinese C. bactrianus are still limited, and molecular biology research on this species is mainly focused on modern specimens. In this study, we retrieved the complete mitochondrial genome from a C. bactrianus specimen, which was excavated from northwestern China and dated at 1290-1180 cal. Phylogenetic analyses using 18 mitochondrial genomes indicated that the C. bactrianus clade was divided into two maternal lineages. The majority of samples originating from Iran to Japan and Mongolia belong to subclade A1, while our sample together with two Mongolian individuals formed the much smaller subclade A2. Furthermore, the divergence time of these two maternal lineages was estimated as 165 Kya (95% credibility interval 117-222 Kya), this might indicate that several different evolutionary lineages were incorporated into the domestic gene pool during the initial domestication process. Bayesian skyline plot (BSP) analysis a slow increase in female effective population size of C. bactrianus from 5000 years ago, which to the beginning of domestication of C. bactrianus. The present study also revealed that there were extensive exchanges of genetic information among C. bactrianus populations in regions along the Silk Road.
KW  - Camelus bactrianus
KW  - mitochondrial genome
KW  - ancient DNA
KW  - phylogeny
KW  - maternal lineages
Y1  - 2019
U6  - https://doi.org/10.1080/24701394.2019.1659250
SN  - 2470-1394
SN  - 2470-1408
VL  - 30
IS  - 7
SP  - 786
EP  - 793
PB  - Routledge, Taylor & Francis Group
CY  - Abingdon
ER  - 
TY  - JOUR
A1  - Beaumont, Robin N.
A1  - Warrington, Nicole M.
A1  - Cavadino, Alana
A1  - Tyrrell, Jessica
A1  - Nodzenski, Michael
A1  - Horikoshi, Momoko
A1  - Geller, Frank
A1  - Myhre, Ronny
A1  - Richmond, Rebecca C.
A1  - Paternoster, Lavinia
A1  - Bradfield, Jonathan P.
A1  - Kreiner-Moller, Eskil
A1  - Huikari, Ville
A1  - Metrustry, Sarah
A1  - Lunetta, Kathryn L.
A1  - Painter, Jodie N.
A1  - Hottenga, Jouke-Jan
A1  - Allard, Catherine
A1  - Barton, Sheila J.
A1  - Espinosa, Ana
A1  - Marsh, Julie A.
A1  - Potter, Catherine
A1  - Zhang, Ge
A1  - Ang, Wei
A1  - Berry, Diane J.
A1  - Bouchard, Luigi
A1  - Das, Shikta
A1  - Hakonarson, Hakon
A1  - Heikkinen, Jani
A1  - Helgeland, Oyvind
A1  - Hocher, Berthold
A1  - Hofman, Albert
A1  - Inskip, Hazel M.
A1  - Jones, Samuel E.
A1  - Kogevinas, Manolis
A1  - Lind, Penelope A.
A1  - Marullo, Letizia
A1  - Medland, Sarah E.
A1  - Murray, Anna
A1  - Murray, Jeffrey C.
A1  - Njolstad, Pal R.
A1  - Nohr, Ellen A.
A1  - Reichetzeder, Christoph
A1  - Ring, Susan M.
A1  - Ruth, Katherine S.
A1  - Santa-Marina, Loreto
A1  - Scholtens, Denise M.
A1  - Sebert, Sylvain
A1  - Sengpiel, Verena
A1  - Tuke, Marcus A.
A1  - Vaudel, Marc
A1  - Weedon, Michael N.
A1  - Willemsen, Gonneke
A1  - Wood, Andrew R.
A1  - Yaghootkar, Hanieh
A1  - Muglia, Louis J.
A1  - Bartels, Meike
A1  - Relton, Caroline L.
A1  - Pennell, Craig E.
A1  - Chatzi, Leda
A1  - Estivill, Xavier
A1  - Holloway, John W.
A1  - Boomsma, Dorret I.
A1  - Montgomery, Grant W.
A1  - Murabito, Joanne M.
A1  - Spector, Tim D.
A1  - Power, Christine
A1  - Jarvelin, Marjo-Ritta
A1  - Bisgaard, Hans
A1  - Grant, Struan F. A.
A1  - Sorensen, Thorkild I. A.
A1  - Jaddoe, Vincent W.
A1  - Jacobsson, Bo
A1  - Melbye, Mads
A1  - McCarthy, Mark I.
A1  - Hattersley, Andrew T.
A1  - Hayes, M. Geoffrey
A1  - Frayling, Timothy M.
A1  - Hivert, Marie-France
A1  - Felix, Janine F.
A1  - Hypponen, Elina
A1  - Lowe, William L.
A1  - Evans, David M.
A1  - Lawlor, Debbie A.
A1  - Feenstra, Bjarke
A1  - Freathy, Rachel M.
T1  - Genome-wide association study of offspring birth weight in 86 577 women identifies five novel loci and highlights maternal genetic effects that are independent of fetal genetics
JF  - Human molecular genetics
N2  - Genome-wide association studies of birth weight have focused on fetal genetics, whereas relatively little is known about the role of maternal genetic variation. We aimed to identify maternal genetic variants associated with birth weight that could highlight potentially relevant maternal determinants of fetal growth. We meta-analysed data on up to 8.7 million SNPs in up to 86 577 women of European descent from the Early Growth Genetics (EGG) Consortium and the UK Biobank. We used structural equation modelling (SEM) and analyses of mother-child pairs to quantify the separate maternal and fetal genetic effects. Maternal SNPs at 10 loci (MTNR1B, HMGA2, SH2B3, KCNAB1, L3MBTL3, GCK, EBF1, TCF7L2, ACTL9, CYP3A7) were associated with offspring birth weight at P< 5 x 10(-8). In SEM analyses, at least 7 of the 10 associations were consistent with effects of the maternal genotype acting via the intrauterine environment, rather than via effects of shared alleles with the fetus. Variants, or correlated proxies, at many of the loci had been previously associated with adult traits, including fasting glucose (MTNR1B, GCK and TCF7L2) and sex hormone levels (CYP3A7), and one (EBF1) with gestational duration. The identified associations indicate that genetic effects on maternal glucose, cytochrome P450 activity and gestational duration, and potentially on maternal blood pressure and immune function, are relevant for fetal growth. Further characterization of these associations in mechanistic and causal analyses will enhance understanding of the potentially modifiable maternal determinants of fetal growth, with the goal of reducing the morbidity and mortality associated with low and high birth weights.
Y1  - 2018
U6  - https://doi.org/10.1093/hmg/ddx429
SN  - 0964-6906
SN  - 1460-2083
VL  - 27
IS  - 4
SP  - 742
EP  - 756
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - GEN
A1  - Beaumont, Robin N.
A1  - Warrington, Nicole M.
A1  - Cavadino, Alana
A1  - Tyrrell, Jessica
A1  - Nodzenski, Michael
A1  - Horikoshi, Momoko
A1  - Geller, Frank
A1  - Myhre, Ronny
A1  - Richmond, Rebecca C.
A1  - Paternoster, Lavinia
A1  - Bradfield, Jonathan P.
A1  - Kreiner-Møller, Eskil
A1  - Huikari, Ville
A1  - Metrustry, Sarah
A1  - Lunetta, Kathryn L.
A1  - Painter, Jodie N.
A1  - Hottenga, Jouke-Jan
A1  - Allard, Catherine
A1  - Barton, Sheila J.
A1  - Espinosa, Ana
A1  - Marsh, Julie A.
A1  - Potter, Catherine
A1  - Zhang, Ge
A1  - Ang, Wei
A1  - Berry, Diane J.
A1  - Bouchard, Luigi
A1  - Das, Shikta
A1  - Hakonarson, Hakon
A1  - Heikkinen, Jani
A1  - Helgeland, Øyvind
A1  - Hocher, Berthold
A1  - Hofman, Albert
A1  - Inskip, Hazel M.
A1  - Jones, Samuel E.
A1  - Kogevinas, Manolis
A1  - Lind, Penelope A.
A1  - Marullo, Letizia
A1  - Medland, Sarah E.
A1  - Murray, Anna
A1  - Murray, Jeffrey C.
A1  - Njølstad, Pa ̊l R.
A1  - Nohr, Ellen A.
A1  - Reichetzeder, Christoph
A1  - Ring, Susan M.
A1  - Ruth, Katherine S.
A1  - Santa-Marina, Loreto
A1  - Scholtens, Denise M.
A1  - Sebert, Sylvain
A1  - Sengpiel, Verena
A1  - Tuke, Marcus A.
A1  - Vaudel, Marc
A1  - Weedon, Michael N.
A1  - Willemsen, Gonneke
A1  - Wood, Andrew R.
A1  - Yaghootkar, Hanieh
A1  - Muglia, Louis J.
A1  - Bartels, Meike
A1  - Relton, Caroline L.
A1  - Pennell, Craig E.
A1  - Chatzi, Leda
A1  - Estivill, Xavier
A1  - Holloway, John W.
A1  - Boomsma, Dorret I.
A1  - Montgomery, Grant W.
A1  - Murabito, Joanne M.
A1  - Spector, Tim D.
A1  - Power, Christine
A1  - Ja ̈rvelin, Marjo-Ritta
A1  - Bisgaard, Hans
A1  - Grant, Struan F.A.
A1  - Sørensen, Thorkild I.A.
A1  - Jaddoe, Vincent W.
A1  - Jacobsson, Bo
A1  - Melbye, Mads
A1  - McCarthy, Mark I.
A1  - Hattersley, Andrew T.
A1  - Hayes, M. Geoffrey
A1  - Frayling, Timothy M.
A1  - Hivert, Marie-France
A1  - Felix, Janine F.
A1  - Hyppo ̈nen, Elina
A1  - Lowe, William L. , Jr
A1  - Evans, David M.
A1  - Lawlor, Debbie A.
A1  - Feenstra, Bjarke
A1  - Freathy, Rachel M.
T1  - Genome-wide association study of offspring birth weight in 86 577 women identifies five novel loci and highlights maternal genetic effects that are independent of fetal genetics
T2  - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe
N2  - Genome-wide association studies of birth weight have focused on fetal genetics, whereas relatively little is known about the role of maternal genetic variation. We aimed to identify maternal genetic variants associated with birth weight that could highlight potentially relevant maternal determinants of fetal growth. We meta-analysed data on up to 8.7 million SNPs in up to 86 577 women of European descent from the Early Growth Genetics (EGG) Consortium and the UK Biobank. We used structural equation modelling (SEM) and analyses of mother–child pairs to quantify the separate maternal and fetal genetic effects. Maternal SNPs at 10 loci (MTNR1B, HMGA2, SH2B3, KCNAB1, L3MBTL3, GCK, EBF1, TCF7L2, ACTL9, CYP3A7) were associated with offspring birth weight at P < 5 Â 10 À8 . In SEM analyses, at least 7 of the 10 associations were consistent with effects of the maternal genotype acting via the intrauterine environment, rather than via effects of shared alleles with the fetus. Variants, or correlated proxies, at many of the loci had been previously associated with adult traits, including fasting glucose (MTNR1B, GCK and TCF7L2) and sex hormone levels (CYP3A7), and one (EBF1) with gestational duration. The identified associations indicate that genetic effects on maternal glucose, cytochrome P450 activity and gestational duration, and potentially on maternal blood pressure and immune function, are relevant for fetal growth. Further characterization of these associations in mechanistic and causal analyses will enhance understanding of the potentially modifiable maternal determinants of fetal growth, with the goal of reducing the morbidity and mortality associated with low and high birth weights.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 628 
KW  - alleles
KW  - birth weight
KW  - fetus
KW  - genotype
KW  - mothers
KW  - single nucleotide polymorphism
KW  - genetics
KW  - duration of gestation
KW  - genome-wide association study
KW  - offspring
KW  - biobanks
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-423100
SN  - 1866-8372
IS  - 628
ER  - 
TY  - JOUR
A1  - Wolff, Martin
A1  - Zhang-Haagen, Bo
A1  - Decker, Christina
A1  - Barz, Bogdan
A1  - Schneider, Mario
A1  - Biehl, Ralf
A1  - Radulescu, Aurel
A1  - Strodel, Birgit
A1  - Willbold, Dieter
A1  - Nagel-Steger, Luitgard
T1  - A beta 42 pentamers/hexamers are the smallest detectable oligomers in solution
JF  - Scientific reports
Y1  - 2017
U6  - https://doi.org/10.1038/s41598-017-02370-3
SN  - 2045-2322
VL  - 7
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - THES
A1  - Zhang, Bo
T1  - Magnetic fields near microstructured surfaces : application to atom chips
T1  - Magnetische Felder in der Nähe von microstrukturierten Oberflächen : Anwendung auf Atomchips
N2  - Microfabricated solid-state surfaces, also called atom chip', have become a well-established technique to trap and manipulate atoms. This has simplified applications in atom interferometry, quantum information processing, and studies of many-body systems. Magnetic trapping potentials with arbitrary geommetries are generated with atom chip by miniaturized current-carrying conductors integrated on a solid substrate. Atoms can be trapped and cooled to microKelvin and even nanoKelvin temperatures in such microchip trap. However, cold atoms can be significantly perturbed by the chip surface, typically held at room temperature. The magnetic field fluctuations generated by thermal currents in the chip elements may induce spin flips of atoms and result in loss, heating and decoherence. In this thesis, we extend previous work on spin flip rates induced by magnetic noise and consider the more complex geometries that are typically encountered in atom chips: layered structures and metallic wires of finite cross-section. We also discuss a few aspects of atom chips traps built with superconducting structures that have been suggested as a means to suppress magnetic field fluctuations. The thesis describes calculations of spin flip rates based on magnetic Green functions that are computed analytically and numerically. For a chip with a top metallic layer, the magnetic noise depends essentially on the thickness of that layer, as long as the layers below have a much smaller conductivity. Based on this result, scaling laws for loss rates above a thin metallic layer are derived. A good agreement with experiments is obtained in the regime where the atom-surface distance is comparable to the skin depth of metal. Since in the experiments, metallic layers are always etched to separate wires carrying different currents, the impact of the finite lateral wire size on the magnetic noise has been taken into account. The local spectrum of the magnetic field near a metallic microstructure has been investigated numerically with the help of boundary integral equations. The magnetic noise significantly depends on polarizations above flat wires with finite lateral width, in stark contrast to an infinitely wide wire. Correlations between multiple wires are also taken into account. In the last part, superconducting atom chips are considered. Magnetic traps generated by superconducting wires in the Meissner state and the mixed state are studied analytically by a conformal mapping method and also numerically. The properties of the traps created by superconducting wires are investigated and compared to normal conducting wires: they behave qualitatively quite similar and open a route to further trap miniaturization, due to the advantage of low magnetic noise. We discuss critical currents and fields for several geometries.
N2  - Mikrotechnologische Oberflächen, sogenannte Atomchips, sind eine etablierte Methode zum Speichern und Manipulieren von Atomen geworden. Das hat Anwendungen in der Atom-Interferometrie, Quanteninformationsverarbeitung und Vielteilchensystemen vereinfacht. Magnetische Fallenpotentiale mit beliebigen Geometrien werden durch Atomchips mit miniaturisierten stromführenden Leiterbahnen auf einer Festkörperunterlage realisiert. Atome können bei Temperaturen im $\mu$ K oder sogar nK-Bereich in einer solchen Falle gespeichert und gekühlt werden. Allerdings können kalte Atome signifikant durch die Chip-Oberfläche gestört werden, die sich typischerweise auf Raumtemperatur befindet. Die durch thermische Ströme im Chip erzeugten magnetischen Feldfluktuationen können Spin-Flips der Atome induzieren und Verlust, Erwärmung und Dekohärenz zur Folge haben. In dieser Dissertation erweitern wir frühere Arbeiten über durch magnetisches Rauschen induzierte Spin-Flip-Ratenund betrachten kompliziertere Geometrien, wie sie typischerweise auf einem Atom-Chip anzutreffen sind: Geschichtete Strukturen und metallische Leitungen mit endlichem Querschnitt. Wir diskutieren auch einige Aspekte von Aomchips aus Supraleitenden Strukturen die als Mittel zur Unterdrückung magnetischer Feldfluktuationen vorgeschlagen wurden. Die Arbeit beschreibt analytische und numerische Rechnungen von Spin-Flip Raten auf Grundlage magnetischer Greensfunktionen. Für einen Chip mit einem metallischen Top-Layer hängt das magnetische Rauschen hauptsächlich von der Dicke des Layers ab, solange die unteren Layer eine deutlich kleinere Leitfähigkeit haben. Auf Grundlage dieses Ergebnisses werden Skalengesetze für Verlustraten über einem dünnen metallischen Leiter hergeleitet. Eine gute Übereinstimmung mit Experimenten wird in dem Bereich erreicht, wo der Abstand zwischen Atom und Oberfläche in der Größenordnung der Eindringtiefe des Metalls ist. Da in Experimenten metallische Layer immer geätzt werden, um verschiedene stromleitende Bahnen vonenander zu trennen, wurde der Einfluß eines endlichen Querschnittsauf das magnetische Rauschen berücksichtigt. Das lokale Spektrum des magnetischen Feldes in der Nähe einer metallischen Mikrostruktur wurde mit Hilfe von Randintegralen numerisch untersucht. Das magnetische Rauschen hängt signifikant von der Polarisierung über flachen Leiterbahnen mit endlichem Querschnitt ab, im Unterschied zu einem unendlich breiten Leiter. Es wurden auch Korrelationen zwischen mehreren Leitern berücksichtigt. Im letzten Teil werden supraleitende Atomchips betrachtet. Magnetische Fallen, die von supraleitenden Bahnen im Meissner Zustand und im gemischten Zustand sind werden analytisch durch die Methode der konformen Abbildung und numerisch untersucht. Die Eigenschaften der durch supraleitende Bahnen erzeugten Fallen werden erforscht und mit normal leitenden verglichen: Sie verhalten sich qualitativ sehr ähnlich und öffnen einen Weg zur weiteren Miniaturisierung von Fallen, wegen dem Vorteil von geringem magnetischem Rauschen. Wir diskutieren kritische Ströme und Felder für einige Geometrien.
KW  - Magnetische Felder
KW  - Atom chip
KW  - Supraleiter
KW  - magnetisches Rauschen
KW  - microstrukturierte Oberfläche
KW  - magnetic fields
KW  - atom chip
KW  - superconductors
KW  - magnetic noise
KW  - microstructured surface
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-28984
ER  - 
TY  - JOUR
A1  - Zhang, Bo
A1  - Henkel, Carsten
T1  - Magnetic noise around metallic microstructures
N2  - We compute the local spectrum of the magnetic field near a metallic microstructure at finite temperature. Our main focus is on deviations from a plane-layered geometry for which we review the main properties. Arbitrary geometries are handled with the help of numerical calculations based on surface integral equations. The magnetic noise shows a significant polarization anisotropy above flat wires with finite lateral width, in stark contrast to an infinitely wide wire. Within the limits of a two-dimensional setting, our results provide accurate estimates for loss and dephasing rates in so-called `atom chip traps' based on metallic wires. A simple approximation based on the incoherent summation of local current elements gives qualitative agreement with the numerics, but fails to describe current correlations among neighboring objects.
Y1  - 2007
UR  - http://dx.doi.org/10.1063/1.2800174
U6  - https://doi.org/10.1063/1.2800174
SN  - 0021-8979
ER  -