51
|
Martinelli A, Artini C, Keller L. New insights into the magnetic properties of LaErO3, (La0.5Er0.5)2O3 and (La0.5Dy0.5)2O3 oxides. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:066003. [PMID: 26796300 DOI: 10.1088/0953-8984/28/6/066003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Orthorhombic LaErO3 and cubic (La0.5 Ln 0.5)2O3 oxides (Ln: Er, Dy) were examined by neutron powder diffraction between 1.5 K and 15 K in order to investigate their crystallographic and magnetic structures. At 1.5 K both LaErO3 and (La0.5Er0.5)2O3 display a magnetic moments ordering, whereas for (La0.5Dy0.5)2O3 only short range magnetic correlations can be argued, suggesting a possible magnetic moments ordering at lower temperature. LaErO3 is characterized by a magnetic wavevector k = (0, 0, 0) and forms an antiferromagnetic G x C y A z -type structure belonging to the [Formula: see text] Shubnikov group with a total magnetic moment of 6.78(3) μ B. The antiferromagnetic structure of (La0.5Er0.5)2O3 is similar to the one typical of Er2O3, with a total magnetic moment of 4.28(2) μ B at both different magnetic sites; it is characterized by k = (0, 0, 0) and belongs to the magnetic [Formula: see text] Shubnikov group.
Collapse
|
52
|
Baranov NV, Ibrahim PNG, Selezneva NV, Gubkin AF, Volegov AS, Shishkin DA, Keller L, Sheptyakov D, Sherstobitova EA. Layer-preferential substitutions and magnetic properties of pyrrhotite-type Fe7-yMyX8 chalcogenides (X = S, Se; M = Ti, Co). JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:286003. [PMID: 26125410 DOI: 10.1088/0953-8984/27/28/286003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A comparative study of four series of pyrrhotite-type chalcogenide compounds Fe(7-y)M(y)X(8) (X = S, Se) with substitution of Ti or Co for iron has been performed by means of x-ray and neutron powder diffraction, and by magnetization measurements. In Fe(7-y)M(y)X(8) compounds having a ferrimagnetic order at y = 0, the substitution of either Ti or Co for iron is observed to result in a monotonous decrease of the magnetic ordering temperature, while the resultant magnetization shows a non-monotonous behavior with a minimum around y = 1.0-1.5 in all the Fe(7-y)M(y)X(8) families except Fe(7-y)Co(y)Se(8). Suppression of a magnetically ordered state with substitutions in Fe(7-y)M(y)X(8) is ascribed to nearly zero values of Ti and Co magnetic moments, while the non-monotonous changes of the resultant magnetization are explained by the compensation of the sublattice magnetizations due to the non-random substitutions in alternating metallic layers. The difference in the cation partitioning observed in Fe(7-y)Ti(y)X(8) and Fe(7-y)Co(y)X(8) is attributed to the difference in the spatial extension of Ti and Co 3d orbitals. High coercive field values (20-24 kOe) observed at low temperatures in the Ti-containing compounds Fe(7-y)Ti(y)X(8) with y ⩾ 3 are suggested to result from the enhancement of Fe orbital moment due to the Ti for Fe substitution.
Collapse
|
53
|
Keller L, Plaza A, Dubiella C, Groll M, Kaiser M, Müller R. Macyranones: Structure, Biosynthesis, and Binding Mode of an Unprecedented Epoxyketone that Targets the 20S Proteasome. J Am Chem Soc 2015; 137:8121-30. [PMID: 26050527 DOI: 10.1021/jacs.5b03833] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In our screening efforts to identify unique scaffolds from myxobacteria for the drug discovery process, we used LC-SPE-NMR-MS techniques to isolate six linear peptides, termed macyranone A-F, from Cystobacter fuscus MCy9118. The macyranones are characterized by a rare 2-methylmalonamide moiety and an α-amino ketone fragment including an α',β'-epoxyketone in macyranone A. Gene disruption experiments confirmed the biosynthetic gene cluster of the macyranones as PKS/NRPS hybrid. Detailed in silico and phylogenetic analysis unraveled that the biosynthesis involves two conspicuous amide bond formations accomplished by an amidotransferase and a unique condensation domain. The gene cluster provides further insights into the formation of the powerful epoxyketone residue involving an acyl-CoA dehydrogenase and an unconventional free-standing thioesterase. Macyranone A was found to inhibit the chymotrypsin-like activity of the yeast 20S proteasome with an IC50 of 5.9 nM and the human constitutive proteasome and immunoproteasome with IC50 values of 21 and 15 nM, respectively. The β5 subunit of the 20S proteasome was characterized as target by X-ray crystallography revealing an irreversible binding mode similar to the natural product epoxomicin. The presence of the methylmalonamide residue facilitates the stabilization of macyranone A with the active β5 subunit of the proteasome. Macyranone A exhibits a potent inhibitory effect against the parasites Trypanosoma brucei rhodesiense and Leishmania donovani with IC50 values of 1.55 and 0.22 μM, respectively.
Collapse
|
54
|
Fu C, Keller L, Bauer A, Brönstrup M, Froidbise A, Hammann P, Herrmann J, Mondesert G, Kurz M, Schiell M, Schummer D, Toti L, Wink J, Müller R. Biosynthetic Studies of Telomycin Reveal New Lipopeptides with Enhanced Activity. J Am Chem Soc 2015; 137:7692-705. [DOI: 10.1021/jacs.5b01794] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
55
|
Keller L, Christie A, Dickinson P. Neuromodulator Permeability of a Ganglionic Sheath in the Lobster,
Homarus americanus. FASEB J 2015. [DOI: 10.1096/fasebj.29.1_supplement.686.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
56
|
Sikolenko V, Troyanchuk I, Bushinsky M, Efimov V, Keller L, White JS, Schilling FR, Schorr S. High pressure induced spin state crossover in Sr2CaYCo4O10.5. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:046005. [PMID: 25567194 DOI: 10.1088/0953-8984/27/4/046005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The layered cobaltite Sr(2)CaYCo(4)O(10.5) with formal average cobalt oxidation state close to 3+ has been studied as functions of both temperature and pressure up to 4 GPa by neutron powder diffraction (NPD). The crystal structure is shown to have tetragonal symmetry (space group I4/mmm; 2a(p) × 2a(p) × 4a(p) superstructure), and the magnetic structure at ambient pressure is found to be G-type antiferromagnetic with TN close to 310 K. The magnetic moments within the CoO(6) octahedral layers and anion-deficient CoO(4.5) layers are 1.2μ(B) and 2.8μ(B), respectively. At 25 K, and applied pressure of 3.5 GPa is sufficient to completely suppress a long-range magnetic order. This result is interpreted in terms of a pressure-induced high-to-low spin state crossover of the Co(3+) ions.
Collapse
|
57
|
Lucas C, Nicolas M, Keller L. Expression of foraging and Gp-9 are associated with social organization in the fire ant Solenopsis invicta. INSECT MOLECULAR BIOLOGY 2015; 24:93-104. [PMID: 25315753 DOI: 10.1111/imb.12137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The aim of this study was to investigate levels of expression of two major genes, the odorant binding protein Gp-9 (general protein-9) and foraging, that have been shown to be associated with behavioural polymorphisms in ants. We analysed workers and young nonreproductive queens collected from nests of the monogyne (single reproductive queen per nest) and polygyne (multiple reproductive queens) social forms of Solenopsis invicta. In workers but not young queens, the level of foraging expression was significantly associated with social form and the task performed (ie localization in the nest or foraging area). The level of expression of Gp-9 was also associated with social form and worker localization. In addition there was a higher level of expression of the Gp-9(b) allele compared with the Gp-9(B) allele in the heterozygote workers and the young nonreproductive queens. Finally, in the polygyne colonies the level of expression of foraging was not significantly associated with the Gp-9 genotype for either workers or young nonreproductive queens, suggesting that both genes have independent non-epistatic effects on behaviour in S. invicta.
Collapse
|
58
|
Piskorz D, Bongarzoni L, Citta L, Citta N, Citta P, Keller L, Tommasi A, Piskorz G. Guías ESH/ESC 2007 vs 2013: ¿cambia la práctica para el diagnóstico de hipertrofia ventricular izquierda? HIPERTENSION Y RIESGO VASCULAR 2014. [DOI: 10.1016/j.hipert.2014.04.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|
59
|
Panosyan E, Gotesman M, Kallay T, Martinez S, Bolaris M, Lasky J, Fouyssac F, Gentet JC, Frappaz D, Piguet C, Gorde-Grosjean S, Grill J, Schmitt E, Pall-Kondolff S, Chastagner P, Dudley R, Torok M, Gallegos D, Liu A, Handler M, Hankinson T, Dudley R, Torok M, Gallegos D, Liu A, Handler M, Hankinson T, Fukuoka K, Yanagisawa T, Suzuki T, Shirahata M, Adachi JI, Mishima K, Fujimaki T, Matsutani M, Sasaki A, Wada S, Nishikawa R, Suzuki M, Kondo A, Miyajima M, Arai H, Morin S, Uro-Coste E, Munzer C, Gambart M, Puget S, Miquel C, Maurage CA, Dufour C, Leblond P, Andre N, Kanold J, Icher C, Bertozzi AAI, Diez B, Muggeri A, Cerrato S, Calabrese B, Arakaki N, Marron A, Sevlever G, Fisher MJ, Widemann BC, Dombi E, Wolters P, Cantor A, Vinks A, Parentesis J, Ullrich N, Gutmann D, Viskochil D, Tonsgard J, Korf B, Packer R, Weiss B, Fisher MJ, Marcus L, Weiss B, Kim A, Dombi E, Baldwin A, Whitcomb P, Martin S, Gillespie A, Doyle A, Widemann BC, Bulwer C, Gan HW, Ederies A, Korbonits M, Powell M, Jeelani O, Jacques T, Stern E, Spoudeas H, Kimpo M, Tang J, Tan CL, Yeo TT, Chong QT, Ruland V, Hartung S, Kordes U, Wolff JE, Paulus W, Hasselblatt M, Patil S, Zaky W, Khatua S, Lassen-Ramshad Y, Christensen L, Clausen N, Bendel A, Dobyns W, Bennett J, Reyes-Mugica M, Petronio J, Nikiforova M, Mueller H, Kirches E, Korshunov A, Pfister S, Mawrin C, Hemenway M, Foreman N, Kumar A, Kalra S, Acharya R, Radhakrishnan N, Sachdeva A, Nimmervoll B, Hadjadj D, Tong Y, Shelat AA, Low J, Miller G, Stewart CF, Guy RK, Gilbertson RJ, Miwa T, Nonaka Y, Oi S, Sasaki H, Yoshida K, Northup R, Klesse L, McNall-Knapp R, Blagia M, Romeo F, Toscano S, D'Agostino A, Lafay-Cousin L, Lindzon G, Bouffet E, Taylor M, Hader W, Nordal R, Hawkins C, Laperriere N, Laughlin S, Shash H, McDonald P, Wrogemann J, Ahsanuddin A, Matsuda K, Soni R, Vanan MI, Cohen K, Taylor I, Rodriguez F, Burger P, Yeh J, Rao S, Iskandar B, Kienitz BA, Bruce R, Keller L, Salamat S, Puccetti D, Patel N, Hana A, Gunness VRN, Berthold C, Hana A, Bofferding L, Neuhaeuser C, Scalais E, Kieffer I, Feiden W, Graf N, Boecher-Schwarz H, Hertel F, Cruz O, Morales A, de Torres C, Vicente A, Gonzalez MA, Sunol M, Mora J, Garcia G, Guillen A, Muchart J, Yankelevich M, Sood S, Diver J, Savasan S, Poulik J, Bhambhani K, Hochart A, Gaillard V, Bonne NX, Baroncini M, Andre N, Vannier JP, Dubrulle F, Lejeune JP, Vincent C, Leblond P, Japp A, Gessi M, Muehlen AZ, Klein-Hitpass L, Pietsch T, Sharma M, Yadav R, Malgulwar PB, Pathak P, Sigamani E, Suri V, Sarkar C, Jagdevan A, Singh M, Sharma BS, Garg A, Bakhshi S, Faruq M, Doromal D, Villafuerte CJ, Tezcanli E, Yilmaz M, Sengoz M, Peker S, Dhall G, Robison N, Margol A, Evans A, Krieger M, Finlay J, Rosser T, Khakoo Y, Pratilas C, Marghoob A, Berger M, Hollmann T, Rosenblum M, Mrugala M, Giglio P, Keene C, Ferreira M, Garcia D, Weil A, Khatib Z, Diaz A, Niazi T, Bhatia S, Ragheb J, Robison N, Rangan K, Margol A, Rosser T, Finlay J, Dhall G, Gilles F, Morris C, Chen Y, Shetty V, Elbabaa S, Guzman M, Abdel-Baki MS, Abdel-Baki MS, Waguespack S, Jones J, Stapleton S, Baskin D, M, Okcu F. RARE TUMOURS. Neuro Oncol 2014. [DOI: 10.1093/neuonc/nou081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
60
|
Eap S, Keller L, Ferrand A, Schiavi J, Lahiri D, Lemoine S, Facca S, Fioretti F, Mainard D, Agarwal A, Benkirane-Jessel N. Nanomechanical Properties of Active Nanofibrous Implants After In Vivo Bone Regeneration. ACTA ACUST UNITED AC 2014. [DOI: 10.1142/s1793984414500019] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
With the aging of the population and a correlated increase in the incidence of osteoarticular damage, great attention is focused on regenerative nanomedicine solutions to restore durable articular function and comfort. A durable cartilage repair is not effective without regeneration of an intact subchondral bed along with the surface chondral regeneration. Our expected outcomes are the development of clinical applications in the field of tissue engineering and nanomedicine, and more particularly in bone-cartilage unit regeneration. Here we report for the first time the nanomechanical analysis of the retrieved active implant after subchondral bone regeneration in vivo, which is much more efficient and long lasting solution to osteochondral defects than the existing ones. We believe that our results make a significant contribution to the area of regenerative nanomedicine. The concepts discovered here may serve to design sophisticated implants for placement into a broad variety of tissues.
Collapse
|
61
|
Romiguier J, Lourenco J, Gayral P, Faivre N, Weinert LA, Ravel S, Ballenghien M, Cahais V, Bernard A, Loire E, Keller L, Galtier N. Population genomics of eusocial insects: the costs of a vertebrate-like effective population size. J Evol Biol 2014; 27:593-603. [DOI: 10.1111/jeb.12331] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Revised: 12/27/2013] [Accepted: 01/02/2014] [Indexed: 12/15/2022]
|
62
|
Lambert JC, Ibrahim-Verbaas CA, Harold D, Naj AC, Sims R, Bellenguez C, DeStafano AL, Bis JC, Beecham GW, Grenier-Boley B, Russo G, Thorton-Wells TA, Jones N, Smith AV, Chouraki V, Thomas C, Ikram MA, Zelenika D, Vardarajan BN, Kamatani Y, Lin CF, Gerrish A, Schmidt H, Kunkle B, Dunstan ML, Ruiz A, Bihoreau MT, Choi SH, Reitz C, Pasquier F, Cruchaga C, Craig D, Amin N, Berr C, Lopez OL, De Jager PL, Deramecourt V, Johnston JA, Evans D, Lovestone S, Letenneur L, Morón FJ, Rubinsztein DC, Eiriksdottir G, Sleegers K, Goate AM, Fiévet N, Huentelman MW, Gill M, Brown K, Kamboh MI, Keller L, Barberger-Gateau P, McGuiness B, Larson EB, Green R, Myers AJ, Dufouil C, Todd S, Wallon D, Love S, Rogaeva E, Gallacher J, St George-Hyslop P, Clarimon J, Lleo A, Bayer A, Tsuang DW, Yu L, Tsolaki M, Bossù P, Spalletta G, Proitsi P, Collinge J, Sorbi S, Sanchez-Garcia F, Fox NC, Hardy J, Deniz Naranjo MC, Bosco P, Clarke R, Brayne C, Galimberti D, Mancuso M, Matthews F, Moebus S, Mecocci P, Del Zompo M, Maier W, Hampel H, Pilotto A, Bullido M, Panza F, Caffarra P, Nacmias B, Gilbert JR, Mayhaus M, Lannefelt L, Hakonarson H, Pichler S, Carrasquillo MM, Ingelsson M, Beekly D, Alvarez V, Zou F, Valladares O, Younkin SG, Coto E, Hamilton-Nelson KL, Gu W, Razquin C, Pastor P, Mateo I, Owen MJ, Faber KM, Jonsson PV, Combarros O, O'Donovan MC, Cantwell LB, Soininen H, Blacker D, Mead S, Mosley TH, Bennett DA, Harris TB, Fratiglioni L, Holmes C, de Bruijn RF, Passmore P, Montine TJ, Bettens K, Rotter JI, Brice A, Morgan K, Foroud TM, Kukull WA, Hannequin D, Powell JF, Nalls MA, Ritchie K, Lunetta KL, Kauwe JS, Boerwinkle E, Riemenschneider M, Boada M, Hiltuenen M, Martin ER, Schmidt R, Rujescu D, Wang LS, Dartigues JF, Mayeux R, Tzourio C, Hofman A, Nöthen MM, Graff C, Psaty BM, Jones L, Haines JL, Holmans PA, Lathrop M, Pericak-Vance MA, Launer LJ, Farrer LA, van Duijn CM, Van Broeckhoven C, Moskvina V, Seshadri S, Williams J, Schellenberg GD, Amouyel P. Meta-analysis of 74,046 individuals identifies 11 new susceptibility loci for Alzheimer's disease. Nat Genet 2013; 45:1452-8. [PMID: 24162737 PMCID: PMC3896259 DOI: 10.1038/ng.2802] [Citation(s) in RCA: 2983] [Impact Index Per Article: 271.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 09/27/2013] [Indexed: 12/12/2022]
Abstract
Eleven susceptibility loci for late-onset Alzheimer's disease (LOAD) were identified by previous studies; however, a large portion of the genetic risk for this disease remains unexplained. We conducted a large, two-stage meta-analysis of genome-wide association studies (GWAS) in individuals of European ancestry. In stage 1, we used genotyped and imputed data (7,055,881 SNPs) to perform meta-analysis on 4 previously published GWAS data sets consisting of 17,008 Alzheimer's disease cases and 37,154 controls. In stage 2, 11,632 SNPs were genotyped and tested for association in an independent set of 8,572 Alzheimer's disease cases and 11,312 controls. In addition to the APOE locus (encoding apolipoprotein E), 19 loci reached genome-wide significance (P < 5 × 10(-8)) in the combined stage 1 and stage 2 analysis, of which 11 are newly associated with Alzheimer's disease.
Collapse
|
63
|
Martinelli A, Masini R, Artini C, Costa GA, Keller L. DC magnetic susceptibility and neutron powder diffraction analysis of the perovskite-type compounds LaYbO₃ and LaHoO₃. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:426005. [PMID: 24080837 DOI: 10.1088/0953-8984/25/42/426005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Magnetization measurements and neutron powder diffraction analyses followed by Rietveld refinement have been carried out in order to investigate the magnetic structures of LaYbO3 and LaHoO3. Both compounds exhibit a negative thermal expansion along the a and b axes. In LaYbO3 Yb(3+) spins order at 2.4 K according to a FyGz-type structure, belonging to the Pn'ma' magnetic space group. Conversely, LaHoO3 is paramagnetic down to 1.5 K.
Collapse
|
64
|
Decanter C, Delesalle C, Leroy-Martin B, Keller L, Dewailly D, Mailliez A. Fertility preservation by controlled ovarian hyperstimulation (COH) without letrozole in young breast cancer patients before adjuvant chemotherapy: preliminary results. Fertil Steril 2013. [DOI: 10.1016/j.fertnstert.2013.07.1467] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
65
|
Acuña-Mendoza S, Martin S, Ribes S, Keller L, Chaussain C, Lebrin L, Lesot H, Poliard A. ES cells-derived ectomesenchymal cells for tooth engineering. BULLETIN DU GROUPEMENT INTERNATIONAL POUR LA RECHERCHE SCIENTIFIQUE EN STOMATOLOGIE & ODONTOLOGIE 2013; 52:e7-e16. [PMID: 25461448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 07/10/2013] [Indexed: 06/04/2023]
Abstract
Recent progresses in stem cell biology and tissue engineering allow considering the possible development of new therapies for compensating the dental tissue losses associated with traumas, pathologies or ageing. The possibility of generating a tooth by mimicking development through reassociations between dental epithelial cells and ectomesenchymal cells derived from the neural crest (NC) has been demonstrated in the mouse. In the search of cell sources to be used for a human transfer, pluripotent stem cells could represent a good alternative. Our study thus focuses on obtaining, ectomesenchymal cells from pluripotent ES cells, capable of promoting tooth histomorphogenesis, when reassociated with a competent dental epithelium. To this end, two ES differentiation protocols, using cyclopamine or a combination of FGF2 and BMP4, have been developed and tested for their capacity to generate such cells. The differentiated ES cells were characterized by quantitative RT-PCR. Both protocols led the cells to acquire in 10 days a mesenchymal-like cell morphology. Rapidly after induction, the cells loose their expression of pluripotent genes while sequentially activating typical NC specifiers. However, the kinetics of gene activation differed between the 2 protocols. Interestingly, Twist, a gene whose expression in the NC is associated with a commitment towards an ectomesenchymal fate, is only activated under the influence of FGF2 and BMP4. Reassociation experiments with a competent epithelium will allow testing the odontogenic potential of the differentiated ES cells. These experiments performed in the mouse system should allow defining a strategy for obtaining odontogenic competent human cells.
Collapse
|
66
|
Yusuf SM, Jain A, Keller L. Field induced incommensurate-to-commensurate magnetic phase transition in Ca₃Co₁.₈Fe₀.₂O₆: a neutron diffraction study. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:146001. [PMID: 23478340 DOI: 10.1088/0953-8984/25/14/146001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Neutron powder diffraction experiments have been performed to investigate the nature of magnetic ordering, as a function of temperature (1.5-100 K) and magnetic field (0, 2 and 4 T), in the compound Ca3Co1.8Fe0.2O6. In zero applied field, the compound orders magnetically in the incommensurate spin density wave (SDW) structure (TN ∼ 20 K). Under an applied field of ∼2 T, an incommensurate-to-commensurate magnetic phase transition has been observed. With a further increase in the magnetic field (∼4 T), the commensurate magnetic structure transforms into a ferrimagnetic structure. In zero applied field, magnetic short-range ordering (SRO) coexists with the SDW long-range ordering (LRO) at all temperatures below TN. In an applied magnetic field (2 and 4 T), SRO is converted into LRO only over the temperature range 12-20 K; however, below ∼12 K, an increase in the volume fraction of the SRO has been observed. The correlation length for the SRO (below ∼12 K) also gets affected by the application of a field.
Collapse
|
67
|
Yaouanc A, Dalmas de Réotier P, Bonville P, Hodges JA, Glazkov V, Keller L, Sikolenko V, Bartkowiak M, Amato A, Baines C, King PJC, Gubbens PCM, Forget A. Dynamical splayed ferromagnetic ground state in the quantum spin ice Yb(2)Sn(2)O(7). PHYSICAL REVIEW LETTERS 2013; 110:127207. [PMID: 25166842 DOI: 10.1103/physrevlett.110.127207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 01/24/2013] [Indexed: 06/03/2023]
Abstract
From magnetic, specific heat, (170)Yb Mössbauer effect, neutron diffraction, and muon spin relaxation measurements on polycrystalline Yb(2)Sn(2)O(7), we show that below the first order transition at 0.15 K all of the Yb(3+) ions are long-range magnetically ordered and each has a moment of 1.1 μ(B) which lies at ≃ 10° to a common fourfold cubic axis. The four sublattice moments have four different directions away from this axis and are therefore noncoplanar. We term this arrangement splayed ferromagnetism. This ground state has a dynamical component with a fluctuation rate in the megahertz range. The net ferromagnetic exchange interaction has an anisotropy that favors the local threefold axis. We discuss our results in terms of the phase diagram proposed by Savary and Balents [Phys. Rev. Lett. 108, 037202 (2012)] for a pyrochlore lattice of Kramers 1/2 effective spins.
Collapse
|
68
|
Hirschmann MT, Keller L, Hirschmann A, Schenk L, Berbig R, Lüthi U, Amsler F, Friederich NF, Arnold MP. One-year clinical and MR imaging outcome after partial meniscal replacement in stabilized knees using a collagen meniscus implant. Knee Surg Sports Traumatol Arthrosc 2013; 21:740-7. [PMID: 23108681 DOI: 10.1007/s00167-012-2259-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 10/16/2012] [Indexed: 11/28/2022]
Abstract
PURPOSE The purpose of the study was to evaluate the clinical and radiological outcomes after medial/lateral collagen meniscus substitution (CMI) at 12 months postoperatively. METHODS Sixty-seven patients (m:f = 47:20, mean age 36 ± 10 years) underwent arthroscopic CMI after previous subtotal medial (n = 55) or lateral meniscectomy (n = 12) due to persistent joint line pain (n = 25) or to prophylactic reasons (n = 42). Clinical follow-up consisted of IKDC score, Tegner score, Lysholm score, and visual analog scale for pain and satisfaction (preinjury, preoperatively, and 12 months postoperatively; follow-up rate 90 %). MRI scans were analyzed according to the Genovese criteria. RESULTS Nineteen patients (29 %) showed a normal (A), 35 nearly normal (B), 5 abnormal (C), and 1 patient severely abnormal total IKDC score (D). The median Tegner preinjury score was 7 (range 2-10) and at follow-up 6 (range 2-10). The mean Lysholm score before surgery was 68 ± 20 and 93 ± 9 at follow-up. Preoperatively, the mean VAS pain was 4.4 ± 3.1 and 2.0 ± 1.0 at follow-up. Clinical failure of the CMI occurred in 3 patients (n = 1 infection, n = 1 failure of the implant, n = 1 chronic synovitis). On MRI, the CMI was completely resorbed in 3 patients (5 %), partially resorbed in 55 (92 %), and entirely preserved in 3 (5 %) patients. In 5 patients (8 %) the CMI was isointense, in 54 (90 %) slightly and 1 (2 %) highly hyperintense. 43 (72 %) patients showed an extrusion of the CMI implant of more than 3 mm. CONCLUSIONS Significant pain relief and functional improvement throughout all scores at 1 year was noted. The CMI undergoes significant remodeling, degradation, resorption, and extrusion in most of the patients. No difference in outcomes between the medial and lateral CMI was observed. LEVEL OF EVIDENCE Prospective therapeutic study, Level IV.
Collapse
|
69
|
Baranov NV, Sherokalova EM, Selezneva NV, Proshkin AV, Gubkin AF, Keller L, Volegov AS, Proskurina EP. Magnetic order, field-induced phase transitions and magnetoresistance in the intercalated compound Fe0.5TiS2. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:066004. [PMID: 23306103 DOI: 10.1088/0953-8984/25/6/066004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Measurements of the magnetic susceptibility, magnetization, electrical resistivity and neutron diffraction have been performed for the compound Fe(0.5)TiS(2) in which Fe atoms are intercalated between S-Ti-S tri-layers. It has been shown that this compound with a monoclinic crystal structure exhibits an antiferromagnetic (AF) ground state below the Néel temperature T(N) ≈ 140 K. Small deviations from the stoichiometry and some disordering effects caused by the additional low-temperature heat treatment do not affect substantially the AF state in Fe(0.5)TiS(2). According to neutron diffraction data the magnetic structure at 2 K is described by the propagation vector k = (1/4,0,1/4). The Fe magnetic moments with a value of (2.9 ± 0.1) μ(B) are directed at an angle of (78.5 ± 1.8)° to the layers. Application of the magnetic field at T < T(N) induces a metamagnetic phase transition to the ferromagnetic (F) state, which is accompanied by the large magnetoresistance effect (|Δρ/ρ| up to 27%). Below 100 K, the field-induced AF-F transition is found to be irreversible, as evidenced by magnetoresistance and neutron diffraction measurements. The magnetization reversal in the metastable F state is accompanied at low temperatures by substantial hysteresis (ΔH ~ 100 kOe) which is associated with the Ising character of Fe ions.
Collapse
|
70
|
Emlen ST, Reeve HK, Keller L. Reproductive skew: disentangling concessions from control. Trends Ecol Evol 2012; 13:458-9. [PMID: 21238389 DOI: 10.1016/s0169-5347(98)01450-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
71
|
Schefer J, Ceretti M, Le Dreau L, Sura R, Prestipino C, Paulus W, Keller L, Conder K, Pomjakushina E, Pederson B. Oxygen diffusion and structural and properties in La 2−xSr xCuO 4+dand La 2CoO 4+d. Acta Crystallogr A 2012. [DOI: 10.1107/s0108767312095268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
|
72
|
Treiman AH, McKay GA, Bogard DD, Mittlefehldt DW, Wang MS, Keller L, Lipschutz ME, Lindstrom MM, Garrison D. Comparison of the LEW88516 and ALHA77005 martian meteorites: Similar but distinct. ACTA ACUST UNITED AC 2012. [DOI: 10.1111/j.1945-5100.1994.tb00771.x] [Citation(s) in RCA: 90] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
73
|
Pfuner F, Gvasaliya SN, Zaharko O, Keller L, Mesot J, Pomjakushin V, Chu JH, Fisher IR, Degiorgi L. Incommensurate magnetic order in TbTe3. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:036001. [PMID: 22156023 DOI: 10.1088/0953-8984/24/3/036001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report a neutron diffraction study of the magnetic phase transitions in the charge-density wave (CDW) TbTe(3) compound. We discover that in the paramagnetic phase there are strong 2D-like magnetic correlations, consistent with the pronounced anisotropy of the chemical structure. A long-range incommensurate magnetic order emerges in TbTe(3) at T(mag1) = 5.78 K as a result of continuous phase transitions. We observe that near the temperature T(mag1) the magnetic Bragg peaks appear around the position (0, 0, 0.24) (or its rational multiples), that is fairly close to the propagation vector (0,0,0.29) associated with the CDW phase transition in TbTe(3). This suggests that correlations leading to the long-range magnetic order in TbTe(3) are linked to the modulations that occur in the CDW state.
Collapse
|
74
|
Pantzar A, Laukka E, Karlsson S, Atti A, Graff C, Keller L, Fratiglioni L, Bäckman L. P-518 - Depression in combination with KIBRA “CC” and CLSTN2 “TT” alleles is associated with poorer episodic memory performance. Eur Psychiatry 2012. [DOI: 10.1016/s0924-9338(12)74685-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
|
75
|
Thieme D, Große J, Keller L, Graw M. Urinary concentrations of ethyl glucuronide and ethyl sulfate as thresholds to determine potential ethanol-induced alteration of steroid profiles. Drug Test Anal 2011; 3:851-6. [DOI: 10.1002/dta.396] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|