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1. Magnetization and spin dynamics of a Cr-based magnetic cluster: Cr$_{7}$Ni

Author

Bianchi, A., Carretta, S., Santini, P., Amoretti, G., Furukawa, Y., Kiuchi, K., Ajiro, Y., Narumi, Y., Kindo, K., Lago, J., Micotti, E., Arosio, P., Lascialfari, A., Borsa, F., Timco, G., and Winpenny, R. E. P.

Subjects
Condensed Matter - Materials Science
Abstract

We study the magnetization and the spin dynamics of the Cr$_7$Ni ring-shaped magnetic cluster. Measurements of the magnetization at high pulsed fields and low temperature are compared to calculations and show that the spin Hamiltonian approach provides a good description of Cr$_7$Ni magnetic molecule. In addition, the phonon-induced relaxation dynamics of molecular observables has been investigated. By assuming the spin-phonon coupling to take place through the modulation of the local crystal fields, it is possible to evaluate the decay of fluctuations of two generic molecular observables. The nuclear spin-lattice relaxation rate $1/T_1$ directly probes such fluctuations, and allows to determine the magnetoelastic coupling strength., Comment: 3 pages, 2 figures, submitted as a contributed article for the Jems conference in Dublin (September 14-19 2008)

Published
2008

2. NMR as a probe of the relaxation of the magnetization in magnetic molecules

Author

Santini, P., Carretta, S., Liviotti, E., Amoretti, G., Carretta, P., Filibian, M., Lascialfari, A., and Micotti, E.

Subjects
Condensed Matter - Materials Science
Abstract

We investigate the time autocorrelation of the molecular magnetization $M(t)$ for three classes of magnetic molecules (antiferromagnetic rings, grids and nanomagnets), in contact with the phonon heat bath. For all three classes, we find that the exponential decay of the fluctuations of $M(t)$, associated with the irreversible exchange of energy with the heat bath, is characterized by a single characteristic time $\tau (T,B)$ for not too high temperature $T$ and field $B$. This is reflected in a nearly single-lorentzian shape of the spectral density of the fluctuations. We show that such fluctuations are effectively probed by NMR, and that our theory explains the recent phenomenological observation by Baek et al. (PRB70, 134434) that the Larmor-frequency dependence of $1/T_1$ data in a large number of AFM rings fits to a single-lorentzian form., Comment: Published as Phys. Rev. Letters 94, 077203 (2005) in slightly reduced form

Published
2004
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3. A consensus protocol for functional connectivity analysis in the rat brain

Author

Grandjean, J., Desrosiers-Gregoire, G., Anckaerts, C., Angeles-Valdez, D., Ayad, F., Barrière, D., Blockx, I., Bortel, A., Broadwater, M., Cardoso, B., Célestine, M., Chavez-Negrete, J., Choi, S., Christiaen, E., Clavijo, P., Colon-Perez, L., Cramer, S., Daniele, T., Dempsey, E., Diao, Y., Doelemeyer, A., Dopfel, D., Dvořáková, L., Falfán-Melgoza, C., Fernandes, F., Fowler, C., Fuentes-Ibañez, A., Garin, C., Gelderman, E., Golden, C., Guo, C., Henckens, M., Hennessy, L., Herman , P., Hofwijks, N., Horien, C., Ionescu, T., Jones, J., Kaesser, J., Kim, E., Lambers, H., Lazari, A., Lee, S., Lillywhite, A., Liu, Y., López-Castro, A., López-Gil , X., Ma, Z., MacNicol, E., Madularu, D., Mandino, F., Marciano, S., McAuslan, M., McCunn, P., McIntosh, A., Meng, X., Meyer-Baese, L., Missault, S., Moro, F., Naessens, D., Nava-Gomez, L., Nonaka, H., Ortiz, J., Paasonen, J., Pais-Roldán, P., Peeters, L., Pereira, M., Perez, P., Pompilus, M., Prior, M., Rakhmatullin, R., Reimann, H., Reinwald, J., Triana Del Rio, R., Rivera-Olvera, A., Ruiz-Pérez, D., Russo, G., Rutten, T., Ryoke, R., Sack, M., Salvan, P., Sanganahalli, B., Schroeter, A., Seewoo , B., Selingue, E., Seuwen, A., Shi, B., Sirmpilatze, N., Smith, J., Smith, C., Sobczak, F., Stenroos, P., Straathof, M., Strobelt, S., Sumiyoshi, A., Takahashi, K., Torres-García, M., Tudela, R., van den Berg, M., van der Marel, K., van Hout, A., Vertullo, R., Vidal, B., Vrooman, R., Wang, X., Wank, I., Watson, D., Yin, T., Zhang, Y., Zurbruegg, S., Achard, S., Alcauter, S., Auer, D., Barbier, E., Baudewig, J., Beckmann, C., Beckmann, N., Becq, G., Blezer, E., Bolbos, R., Boretius, S., Bouvard, S., Budinger, E., Buxbaum, J., Cash, D., Chapman, V., Chuang, K., Ciobanu, L., Coolen, B., Dalley, J., Dhenain, M., Dijkhuizen, R., Esteban, O., Faber, C., Febo, M., Feindel, K., Forloni, G., Fouquet, J., Garza-Villarreal, E., Gass, N., Glennon, J., Gozzi, A., Gröhn, O., Harkin, A., Heerschap, A., Helluy, X., Herfert , K., Heuser, A., Homberg, J., Houwing, D., Hyder, F., Ielacqua, G., Jelescu, I., Johansen-Berg, H., Kaneko, G., Kawashima, R., Keilholz, S., Keliris, G., Kelly, C., Kerskens, C., Khokhar, J., Kind, P., Langlois, J., Lerch, J., López-Hidalgo, M., Manahan-Vaughan, D., Marchand, F., Mars, R., Marsella, G., Micotti , E., Muñoz-Moreno , E., Near, J., Niendorf, T., Otte, W., Pan , W., Prado-Alcalá, R., Quirarte, G., Rodger , J., Rosenow, T., Sampaio-Baptista, C., Sartorius, A., Sawiak, S., Scheenen, T., Shemesh, Shih, Y., Shmuel, A., Soria, G., Stoop, R., Thompson, G., Till, S., Todd, N., Van Der Linden, A., van der Toorn, A., van Tilborg, G., Vanhove, C., Veltien, A., Verhoye, M., Wachsmuth, L., Weber-Fahr, W., Wenk , P., Yu, X., Zerbi , V., Zhang , N., Zhang, B., Zimmer, L., Devenyi, G., Chakravarty, M., and Hess, A.

Subjects
Action, intention, and motor control, General Neuroscience, fmri, Medizin, Stress-related disorders Donders Center for Medical Neuroscience [Radboudumc 13], Human medicine
Abstract

Task-free functional connectivity in animal models provides an experimental framework to examine connectivity phenomena under controlled conditions and allows for comparisons with data modalities collected under invasive or terminal procedures. Currently, animal acquisitions are performed with varying protocols and analyses that hamper result comparison and integration. Here we introduce StandardRat, a consensus rat functional magnetic resonance imaging acquisition protocol tested across 20 centers. To develop this protocol with optimized acquisition and processing parameters, we initially aggregated 65 functional imaging datasets acquired from rats across 46 centers. We developed a reproducible pipeline for analyzing rat data acquired with diverse protocols and determined experimental and processing parameters associated with the robust detection of functional connectivity across centers. We show that the standardized protocol enhances biologically plausible functional connectivity patterns relative to previous acquisitions. The protocol and processing pipeline described here is openly shared with the neuroimaging community to promote interoperability and cooperation toward tackling the most important challenges in neuroscience. The authors pooled resources to identify best practices and develop a new standardized protocol for estimating functional connectivity in rats with magnetic resonance imaging.

Published
2023
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4. Author Correction: A consensus protocol for functional connectivity analysis in the rat brain

Author

Grandjean, J., Desrosiers-Gregoire, G., Anckaerts, C., Angeles-Valdez, D., Ayad, F., Barrière, D., Blockx, I., Bortel, A., Broadwater, M., Cardoso, B., Célestine, M., Chavez-Negrete, J., Choi, S., https://orcid.org/0000-0001-7327-1344, Christiaen, E., Clavijo, P., Colon-Perez, L., Cramer, S., Daniele, T., Dempsey, E., Diao, Y., Doelemeyer, A., Dopfel, D., Dvořáková, L., Falfán-Melgoza, C., Fernandes, F., Fowler, C., Fuentes-Ibañez, A., Garin, C., Gelderman, E., Golden, C., Guo, C., Henckens, M., Hennessy, L., Herman , P., Hofwijks, N., Horien, C., Ionescu, T., Jones, J., Kaesser, J., Kim, E., Lambers, H., Lazari, A., Lee, S., Lillywhite, A., Liu, Y., López-Castro, A., López-Gil , X., Ma, Z., MacNicol, E., Madularu, D., Mandino, F., Marciano, S., McAuslan, M., McCunn, P., McIntosh, A., Meng, X., Meyer-Baese, L., Missault, S., Moro, F., Naessens, D., Nava-Gomez, L., Nonaka, H., Ortiz, J., Paasonen, J., Pais-Roldán, P., https://orcid.org/0000-0002-9381-3048, Peeters, L., Pereira, M., Perez, P., Pompilus, M., Prior, M., Rakhmatullin, R., Reimann, H., Reinwald, J., Triana Del Rio, R., Rivera-Olvera, A., Ruiz-Pérez, D., Russo, G., Rutten, T., Ryoke, R., Sack, M., Salvan, P., Sanganahalli, B., Schroeter, A., Seewoo , B., Selingue, E., Seuwen, A., Shi, B., Sirmpilatze, N., Smith, J., Smith, C., Sobczak, F., Stenroos, P., Straathof, M., Strobelt, S., Sumiyoshi, A., Takahashi, K., Torres-García, M., Tudela, R., van den Berg, M., van der Marel, K., van Hout, A., Vertullo, R., Vidal, B., Vrooman, R., Wang, X., Wank, I., Watson, D., Yin, T., Zhang, Y., Zurbruegg, S., Achard, S., Alcauter, S., Auer, D., Barbier, E., Baudewig, J., Beckmann, C., Beckmann, N., Becq, G., Blezer, E., Bolbos, R., Boretius, S., Bouvard, S., Budinger, E., Buxbaum, J., Cash, D., Chapman, V., Chuang, K., Ciobanu, L., Coolen, B., Dalley, J., Dhenain, M., Dijkhuizen, R., Esteban, O., Faber, C., Febo, M., Feindel, K., Forloni, G., Fouquet, J., Garza-Villarreal, E., Gass, N., Glennon, J., Gozzi, A., Gröhn, O., Harkin, A., Heerschap, A., Helluy, X., Herfert , K., Heuser, A., Homberg, J., Houwing, D., Hyder, F., Ielacqua, G., Jelescu, I., Johansen-Berg, H., Kaneko, G., Kawashima, R., Keilholz, S., Keliris, G., Kelly, C., Kerskens, C., Khokhar, J., Kind, P., Langlois, J., Lerch, J., López-Hidalgo, M., Manahan-Vaughan, D., Marchand, F., Mars, R., Marsella, G., Micotti , E., Muñoz-Moreno , E., Near, J., Niendorf, T., Otte, W., Pan , W., Prado-Alcalá, R., Quirarte, G., Rodger , J., Rosenow, T., Sampaio-Baptista, C., Sartorius, A., Sawiak, S., Scheenen, T., Shemesh, Shih, Y., Shmuel, A., https://orcid.org/0000-0003-3028-6639, Soria, G., Stoop, R., https://orcid.org/0000-0002-3532-1512, Thompson, G., Till, S., Todd, N., Van Der Linden, A., van der Toorn, A., van Tilborg, G., Vanhove, C., Veltien, A., Verhoye, M., Wachsmuth, L., Weber-Fahr, W., Wenk , P., Yu, X., Zerbi , V., Zhang , N., Zhang, B., Zimmer, L., Devenyi, G., Chakravarty, M., and Hess, A.

Subjects
General Neuroscience, Medizin
Abstract

Weitere Nicht-UDE Autoren sind nicht mit aufgeführt. in press

Published
2023
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5. A systems-level analysis highlights microglial activation as a modifying factor in common epilepsies

Author

Altmann, A, Ryten, M, Di Nunzio, M, Ravizza, T, Tolomeo, D, Reynolds, RH, Somani, A, Bacigaluppi, M, Iori, V, Micotti, E, Di Sapia, R, Cerovic, M, Palma, E, Ruffolo, G, Botia, JA, Absil, J, Alhusaini, S, Alvim, MKM, Auvinen, P, Bargallo, N, Bartolini, E, Bender, B, Bergo, FPG, Bernardes, T, Bernasconi, A, Bernasconi, N, Bernhardt, BC, Blackmon, K, Braga, B, Caligiuri, ME, Calvo, A, Carlson, C, Carr, SJA, Cavalleri, GL, Cendes, F, Chen, J, Chen, S, Cherubini, A, Concha, L, David, P, Delanty, N, Depondt, C, Devinsky, O, Doherty, CP, Domin, M, Focke, NK, Foley, S, Franca, W, Gambardella, A, Guerrini, R, Hamandi, K, Hibar, DP, Isaev, D, Jackson, GD, Jahanshad, N, Kalviainen, R, Keller, SS, Kochunov, P, Kotikalapudi, R, Kowalczyk, MA, Kuzniecky, R, Kwan, P, Labate, A, Langner, S, Lenge, M, Liu, M, Martin, P, Mascalchi, M, Meletti, S, Morita-Sherman, ME, O'Brien, TJ, Pariente, JC, Richardson, MP, Rodriguez-Cruces, R, Rummel, C, Saavalainen, T, Semmelroch, MK, Severino, M, Striano, P, Thesen, T, Thomas, RH, Tondelli, M, Tortora, D, Vaudano, AE, Vivash, L, Podewils, F, Wagner, J, Weber, B, Wiest, R, Yasuda, CL, Zhang, G, Zhang, J, Leu, C, Avbersek, A, Thom, M, Whelan, CD, Thompson, P, McDonald, CR, Vezzani, A, Sisodiya, SM, Altmann, A, Ryten, M, Di Nunzio, M, Ravizza, T, Tolomeo, D, Reynolds, RH, Somani, A, Bacigaluppi, M, Iori, V, Micotti, E, Di Sapia, R, Cerovic, M, Palma, E, Ruffolo, G, Botia, JA, Absil, J, Alhusaini, S, Alvim, MKM, Auvinen, P, Bargallo, N, Bartolini, E, Bender, B, Bergo, FPG, Bernardes, T, Bernasconi, A, Bernasconi, N, Bernhardt, BC, Blackmon, K, Braga, B, Caligiuri, ME, Calvo, A, Carlson, C, Carr, SJA, Cavalleri, GL, Cendes, F, Chen, J, Chen, S, Cherubini, A, Concha, L, David, P, Delanty, N, Depondt, C, Devinsky, O, Doherty, CP, Domin, M, Focke, NK, Foley, S, Franca, W, Gambardella, A, Guerrini, R, Hamandi, K, Hibar, DP, Isaev, D, Jackson, GD, Jahanshad, N, Kalviainen, R, Keller, SS, Kochunov, P, Kotikalapudi, R, Kowalczyk, MA, Kuzniecky, R, Kwan, P, Labate, A, Langner, S, Lenge, M, Liu, M, Martin, P, Mascalchi, M, Meletti, S, Morita-Sherman, ME, O'Brien, TJ, Pariente, JC, Richardson, MP, Rodriguez-Cruces, R, Rummel, C, Saavalainen, T, Semmelroch, MK, Severino, M, Striano, P, Thesen, T, Thomas, RH, Tondelli, M, Tortora, D, Vaudano, AE, Vivash, L, Podewils, F, Wagner, J, Weber, B, Wiest, R, Yasuda, CL, Zhang, G, Zhang, J, Leu, C, Avbersek, A, Thom, M, Whelan, CD, Thompson, P, McDonald, CR, Vezzani, A, and Sisodiya, SM

Abstract

AIMS: The causes of distinct patterns of reduced cortical thickness in the common human epilepsies, detectable on neuroimaging and with important clinical consequences, are unknown. We investigated the underlying mechanisms of cortical thinning using a systems-level analysis. METHODS: Imaging-based cortical structural maps from a large-scale epilepsy neuroimaging study were overlaid with highly spatially resolved human brain gene expression data from the Allen Human Brain Atlas. Cell-type deconvolution, differential expression analysis and cell-type enrichment analyses were used to identify differences in cell-type distribution. These differences were followed up in post-mortem brain tissue from humans with epilepsy using Iba1 immunolabelling. Furthermore, to investigate a causal effect in cortical thinning, cell-type-specific depletion was used in a murine model of acquired epilepsy. RESULTS: We identified elevated fractions of microglia and endothelial cells in regions of reduced cortical thickness. Differentially expressed genes showed enrichment for microglial markers and, in particular, activated microglial states. Analysis of post-mortem brain tissue from humans with epilepsy confirmed excess activated microglia. In the murine model, transient depletion of activated microglia during the early phase of the disease development prevented cortical thinning and neuronal cell loss in the temporal cortex. Although the development of chronic seizures was unaffected, the epileptic mice with early depletion of activated microglia did not develop deficits in a non-spatial memory test seen in epileptic mice not depleted of microglia. CONCLUSIONS: These convergent data strongly implicate activated microglia in cortical thinning, representing a new dimension for concern and disease modification in the epilepsies, potentially distinct from seizure control.

Published
2022

6. Neurobiology of disease

Author

Zanier er, Barzago mm, Vegliante g, Romeo m, Restelli e, Bertani i, Natale c, Colnaghi l, Colombo l, Russo l, Micotti e, Fioriti l, Chiesa r, Diomede l, Zanier, Er, Barzago, Mm, Vegliante, G, Romeo, M, Restelli, E, Bertani, I, Natale, C, Colnaghi, L, Colombo, L, Russo, L, Micotti, E, Fioriti, L, Chiesa, R, and Diomede, L

Published
2021

10. Efficacy of acute administration of inhaled argon on traumatic brain injury in mice

Author

Moro, F, Fossi, F, Magliocca, A, Pascente, R, Sammali, E, Baldini, F, Tolomeo, D, Micotti, E, Citerio, G, Stocchetti, N, Fumagalli, F, Magnoni, S, Latini, R, Ristagno, G, Zanier, E, Moro, Federico, Fossi, Francesca, Magliocca, Aurora, Pascente, Rosaria, Sammali, Eliana, Baldini, Federico, Tolomeo, Daniele, Micotti, Edoardo, Citerio, Giuseppe, Stocchetti, Nino, Fumagalli, Francesca, Magnoni, Sandra, Latini, Roberto, Ristagno, Giuseppe, Zanier, Elisa R., Moro, F, Fossi, F, Magliocca, A, Pascente, R, Sammali, E, Baldini, F, Tolomeo, D, Micotti, E, Citerio, G, Stocchetti, N, Fumagalli, F, Magnoni, S, Latini, R, Ristagno, G, Zanier, E, Moro, Federico, Fossi, Francesca, Magliocca, Aurora, Pascente, Rosaria, Sammali, Eliana, Baldini, Federico, Tolomeo, Daniele, Micotti, Edoardo, Citerio, Giuseppe, Stocchetti, Nino, Fumagalli, Francesca, Magnoni, Sandra, Latini, Roberto, Ristagno, Giuseppe, and Zanier, Elisa R.

Abstract

Background: Whilst there has been progress in supportive treatment for traumatic brain injury (TBI), specific neuroprotective interventions are lacking. Models of ischaemic heart and brain injury show the therapeutic potential of argon gas, but it is still not known whether inhaled argon (iAr) is protective in TBI. We tested the effects of acute administration of iAr on brain oedema, tissue micro-environmental changes, neurological functions, and structural outcome in a mouse model of TBI. Methods: Anaesthetised adult C57BL/6J mice were subjected to severe TBI by controlled cortical impact. Ten minutes after TBI, the mice were randomised to 24 h treatments with iAr 70%/O2 30% or air (iCtr). Sensorimotor deficits were evaluated up to 6 weeks post-TBI by three independent tests. Cognitive function was evaluated by Barnes maze test at 4 weeks. MRI was done to examine brain oedema at 3 days and white matter damage at 5 weeks. Microglia/macrophages activation and functional commitment were evaluated at 1 week after TBI by immunohistochemistry. Results: iAr significantly accelerated sensorimotor recovery and improved cognitive deficits 1 month after TBI, with less white matter damage in the ipsilateral fimbria and body of the corpus callosum. Early changes underpinning protection included a reduction of pericontusional vasogenic oedema and of the inflammatory response. iAr significantly reduced microglial activation with increases in ramified cells and the M2-like marker YM1. Conclusions: iAr accelerates recovery of sensorimotor function and improves cognitive and structural outcome 1 month after severe TBI in adult mice. Early effects include a reduction of brain oedema and neuroinflammation in the contused tissue.

Published
2021

13. Inhaled Argon improves neurological outcome in experimental

Author

Fossi, F, Moro, F, Magliocca, A, Micotti, E, Citerio, G, Stocchetti, N, Latini, R, Ristagno, G, Zanier, E, Fossi, F, Moro, F, Magliocca, A, Micotti, E, Citerio, G, Stocchetti, N, Latini, R, Ristagno, G, and Zanier, E

Subjects
Argon, neuroprotection
Published
2019

18. Proton nuclear magnetic resonance investigation of the spin dynamics in cobalt bassed one-dimensional magnetic molecular chains

Author

Lascialfari, A., AldrAldrovandi, S., Micotti, E., Caneschi, A., and Gatteschi, D.

Subjects
Iodine -- Magnetic properties, Iodine -- Research, Nitrogen -- Magnetic properties, Nitrogen -- Research, Oxygen -- Magnetic properties, Oxygen -- Research, Cobalt -- Magnetic properties, Cobalt -- Research, Nuclear magnetic resonance -- Usage, Physics
Abstract

The spin dynamics of the molecular chain Co(hfac)(sub 2)NITPhOMe is investigated by using (super 1)H nuclear magnetic resonance. The existence of a second (faster) relaxation time is confirmed by the SQUID relaxation data for single crystals, which reveals that part of the magnetization relaxes very fast and connot be detected.

Published
2003

19. Inhaled Argon improves neurological outcome in experimental traumatic brain injury

Author

Fossi, F, Moro, F, Magliocca, A, Micotti, E, Citerio, G, Stocchetti, N, Latini, R, Ristagno, G, R Zanier, E, Francesca Fossi, Federico Moro, Aurora Magliocca, Edoardo Micotti, Giuseppe Citerio, Nino Stocchetti, Roberto Latini, Giuseppe Ristagno, Elisa R Zanier, Fossi, F, Moro, F, Magliocca, A, Micotti, E, Citerio, G, Stocchetti, N, Latini, R, Ristagno, G, R Zanier, E, Francesca Fossi, Federico Moro, Aurora Magliocca, Edoardo Micotti, Giuseppe Citerio, Nino Stocchetti, Roberto Latini, Giuseppe Ristagno, and Elisa R Zanier

Published
2019

20. (Super 7)Li nuclear magnetic resonance in the hexairon(III) antiferromagnetic molecular ring Fe6:Li

Author

Lascialfari, A., Borsa, F., Corti, M., Micotti, E., Furukawa, Y., Cornia, A., and Gatteschi, D.

Subjects
Alkali metals -- Research, Alkali metals -- Magnetic properties, Alkali metals -- Thermal properties, Lithium compounds -- Research, Lithium compounds -- Magnetic properties, Lithium compounds -- Thermal properties, Nuclear magnetic resonance -- Analysis, Physics
Abstract

The nuclear magnetic resonance (NMR) of alkali-metal ion nuclei (super 7)Li in magnetic molecular rings is discussed. Slow electronic spin dynamics are found at temperatures of the order of J/k(sub B) in the (super 7)Li and (super 1)H NSLR.

Published
2004

24. 7Li nuclear magnetic resonance in the hexairon(III) antiferromagnetic molecular ring Fe6:Li.

Author

Lascialfari, A., Borsa, F., Corti, M., Micotti, E., Furukawa, Y., Cornia, A., and Gatteschi, D.

Subjects
MAGNETISM, IRON, ANTIFERROMAGNETISM, FERROMAGNETISM, TEMPERATURE
Abstract

The molecular nanomagnet [LiFe6(OCH3)12(dbm)6]B(C6H5)4·5CH2Cl2 (Fe6:Li in short) is formed by six Fe(III) s=5/2 spins arranged in an almost coplanar ring with antiferromagnetic (AFM) nearest-neighbor coupling constant J/kB∼20 K. We report 7Li nuclear magnetic resonance (NMR) spectra and nuclear spin-lattice relaxation rate (NSLR) measurements as a function of temperature from 1.5 to 50 K with applied field H=1.5 T. No evidence of quadrupole effects was found on the 7Li NMR spectrum within the linewidth resolution (∼25 kHz) ruling against a molecular distortion. The 7Li NSLR is compared with the 1H NSLR results in Fe6:Li and in other AFM rings. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2004
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25. Comparative magnetic resonance imaging and histopathological correlates in two SOD1 transgenic mouse models of amyotrophic lateral sclerosis

Author

Caron, I, Micotti, E, Paladini, A, Merlino, G, Plebani, L, Forloni, G, Modo, M, Bendotti, C, Caron, I, Micotti, E, Paladini, A, Merlino, G, Plebani, L, Forloni, G, Modo, M, and Bendotti, C

Abstract

Amyotrophic Lateral Sclerosis (ALS) is a progressive and fatal disease due to motoneuron degeneration. Magnetic resonance imaging (MRI) is becoming a promising non-invasive approach to monitor the disease course but a direct correlation with neuropathology is not feasible in human. Therefore in this study we aimed to examine MRI changes in relation to histopathology in two mouse models of ALS (C57BL6/J and 129S2/SvHsd SOD1G93A mice) with different disease onset and progression. A longitudinal in vivo analysis of T2 maps, compared to ex vivo histological changes, was performed on cranial motor nuclei. An increased T2 value was associated with a significant tissue vacuolization that occurred prior to motoneuron loss in the cranial nuclei of C57 SOD1G93A mice. Conversely, in 129Sv SOD1G93A mice, which exhibit a more severe phenotype, MRI detected a milder increase of T2 value, associated with a milder vacuolization. This suggests that alteration within brainstem nuclei is not predictive of a more severe phenotype in the SOD1G93A mouse model. Using an ex vivo paradigm, Diffusion Tensor Imaging was also applied to study white matter spinal cord degeneration. In contrast to degeneration of cranial nuclei, alterations in white matter and axons loss reflected the different disease phenotype of SOD1G93A mice. The correspondence between MRI and histology further highlights the potential of MRI to monitor progressive motoneuron and axonal degeneration non-invasively in vivo. The identification of prognostic markers of the disease nevertheless requires validation in multiple models of ALS to ensure that these are not merely model-specific. Eventually this approach has the potential to lead to the development of robust and validated non-invasive imaging biomarkers in ALS patients, which may help to monitor the efficacy of therapies.

Published
2015

27. Chiralità: dalle catene di cavatappi magnetici alle molecole di DNA

Author

Cinti F., Rettori A., Pini M.G. Mariani M., Micotti E., Lascialfari A., Papinutto N., Amato A., Caneschi A., Gatteschi D., Affronte M. Lascialfari, N. Papinutto, A. Amato, A. Caneschi, D. Gatteschi, and M. Affronte

Subjects
Transizioni di fase, Magnetismo molecolare
Published
2008

29. Local spin dynamics in magnetic molecular chains studied by NMR and mu SR

Author

Mariani, M, Aldrovandi, S, Corti, M, Lago, J, Lascialfari, A, Micotti, E, Rettori, A, Cinti, F, Amato, A, Baines, C, Bogani, L, Caneschi, A, Cottrell, SP, and Gatteschi, D

Subjects
LATTICE-RELAXATION, NITRONYL NITROXIDES, PHASE-TRANSITIONS, THERMODYNAMIC PROPERTIES, NEAREST-NEIGHBOR
Abstract

We present NMR and mu+SR study of spin dynamics in one-dimensional and quasi-one-dimensional molecular magnets of recent synthesis. In particular, we focus on the so called Gd(hfaC)(3)NIT-R and CoPhOMe magnetic chains families. For Gd-R helimagnets we show some differences between 'weakly frustrated systems' and 'fully frustrated systems'. The different behaviour is due to the different radical inserted in the chains (R = Me, Ph for 'weakly frustrated systems' and R = iPr, Et for 'fully frustrated systems'). The existence of different phase transitions, particularly to 3D long-range magnetic order in Gd-Ph and to chiral order in Gd-iPr, is remarked together with a comparison between results obtained from macroscopic and microscopic investigating techniques. As regards CoPhOMe slowly relaxing chain, the 1 H NMR measurements confirm the freezing of the spins at low temperature, which prevents the 3D long-range order, and display the presence of two relaxation mechanisms related to distinct contributions to the local spin relaxation. (c) 2007 Elsevier B.V. All rights reserved.

Published
2007

31. Low-energy spin dynamics in the giant keplerate molecule {Mo72Fe30}: A muon spin relaxation and H-1 NMR investigation

Author

Lago, J, Micotti, E, Corti, M, Lascialfari, A, Bianchi, A, Carretta, S, Santini, P, Procissi, D, Baek, SH, Kogerler, P, Baines, C, and Amato, A

Subjects
NUCLEAR MAGNETIC RELAXATION, CLUSTERS, MOLYBDENUM-OXIDE, PROTON NMR, SPHERES
Abstract

We present muon spin relaxation and H-1 NMR results on the magnetically frustrated keplerate molecule {Mo72Fe30}, aimed at studying the local spin dynamics as a function of temperature. We find that, in common with other molecular magnets, the relaxation spectrum of this material is characterized by a single dominating electronic correlation time tau. Experiments and theory show that tau has a thermally activated behavior with an activation gap of the order of the energy difference between the lowest-lying rotational bands in this material. This shows that, in the intermediate temperature range just above 1 K, the relaxation of the electronic spin system occurs via Orbach processes involving energy levels belonging to the two lowest-lying rotational bands. Our data thus provide an experimental estimate of the first interband gap.

Published
2007

32. Low-energy spin dynamics in the giant keplerate molecule {Mo72Fe30}: A muon spin relaxation and 1H NMR investigation

Author

Lago, J., Micotti, E., Baines, C., Amato, A., Corti, M., Lascialfari, A., Bianchi, A., Carretta, S., Santini, P., Procissi, D., Baek, S. H., and Kögerler, P.

Subjects
ddc:530
Abstract

We present muon spin relaxation and H-1 NMR results on the magnetically frustrated keplerate molecule {Mo72Fe30}, aimed at studying the local spin dynamics as a function of temperature. We find that, in common with other molecular magnets, the relaxation spectrum of this material is characterized by a single dominating electronic correlation time tau. Experiments and theory show that tau has a thermally activated behavior with an activation gap of the order of the energy difference between the lowest-lying rotational bands in this material. This shows that, in the intermediate temperature range just above 1 K, the relaxation of the electronic spin system occurs via Orbach processes involving energy levels belonging to the two lowest-lying rotational bands. Our data thus provide an experimental estimate of the first interband gap.

Published
2007
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33. Low-energy excitations in the S=(1/2) molecular nanomagnet K6[V15IVAs6O42(H2O)]·8H2O from proton NMR and µSR

Author

Procissi, D., Lascialfari, A., Micotti, E., Bertassi, M., Carretta, P., Furukawa, Y., and Kögerler, P.

Subjects
Caltech Library Services
Abstract

Zero- and longitudinal-field muon-spin-rotation (µSR) and 1H NMR measurements on the S=(1/2) molecular nanomagnet K6[V15IVAs6O42(H2O)]·8H2O are presented. In LF experiments, the muon asymmetry P(t) was fitted by the sum of three different exponential components with fixed weights. The different muon relaxation rates lambdai (i=1,2,3) and the low-field H=0.23 T 1H NMR spin-lattice relaxation rate 1/T1 show a similar behavior for T>50 K: starting from room temperature they increase as the temperature is decreased. The increase of lambdai and 1/T1 can be attributed to the "condensation" of the system toward the lowest-lying energy levels. The gap Delta~550 K between the first and second S=(3/2) excited states was determined experimentally. For T

Published
2006

34. Low-energy excitations in the S=1/2 molecular nanomagnet K-6[(V15As6O42)-As-IV(H2O)]center dot 8H(2)O from proton NMR and mu SR

Author

Procissi, D, Lascialfari, A, Micotti, E, Bertassi, M, Carretta, P, Furukawa, Y, and Kogerler, P

Subjects
DYNAMICS, NUCLEAR MAGNETIC-RELAXATION, HIGH-SPIN MOLECULES, CLUSTER V-15, SINGLE-CRYSTAL
Abstract

Zero- and longitudinal-field muon-spin-rotation (mu SR) and H-1 NMR measurements on the S=1/2 molecular nanomagnet K-6[(V15As6O42)-As-IV(H2O)](.)8H(2)O are presented. In LF experiments, the muon asymmetry P(t) was fitted by the sum of three different exponential components with fixed weights. The different muon relaxation rates lambda(i) (i=1,2,3) and the low-field H=0.23 T H-1 NMR spin-lattice relaxation rate 1/T-1 show a similar behavior for T > 50 K: starting from room temperature they increase as the temperature is decreased. The increase of lambda(i) and 1/T-1 can be attributed to the 'condensation' of the system toward the lowest-lying energy levels. The gap Delta similar to 550 K between the first and second S=3/2 excited states was determined experimentally. For T < 2 K, the muon relaxation rates lambda(i) stay constant, independently of the field value H

Published
2006

35. F-19 NMR and longitudinal field mu SR studies of the spin dynamics in LiY0.998Ho0.002F4

Author

Graf, MJ, Micotti, E, Lascialfari, A, Borsa, F, Barbara, B, and Tkachuk, A

Abstract

It has recently been demonstrated that quantum tunneling of magnetization occurs between the low-lying electro-nuclear energy levels of Ho3+ ions doped into LiYF4. Here, we report F-19 NMR and longitudinal field mu SR measurements on single crystal LiY0.998Ho0.002F4. We observe that the F-19 spin-lattice relaxation rate 1/T-1 is controlled by the fluctuating field of the Ho ion and, consequently, 1/T-1 increases sharply at resonant magnetic field values where the energy levels are predicted to have level crossings/avoided level crossings, in agreement with the magnetization measurements. Complementary to these ongoing NMR studies we have undertaken longitudinal field mu SR measurements. At low magnetic fields, the muon depolarization rate is dominated by strong depolarization due to the formation of F-muon-F bonds, while at higher fields the longitudinal field dominates, and any enhancement of the depolarization rate due to the energy level crossings is very weak. (c) 2005 Elsevier B.V. All rights reserved.

Published
2006

42. Local Spin Moment Distribution in Antiferromagnetic Molecular Rings Probed by NMR

Author

Micotti, E., Furukawa, Y., Kumagai, K., Carretta, S., Lascialfari, A., Borsa, F., Timco, G. A., Winpenny, R. E. P., Micotti, E., Furukawa, Y., Kumagai, K., Carretta, S., Lascialfari, A., Borsa, F., Timco, G. A., and Winpenny, R. E. P.

Abstract

The NMR spectra of 19F and 53Cr have been obtained at low temperatures in a heterometallic substituted antiferromagnetic (AF) ring Cr7Cd with an S=3/2 ground state and compared with the spectra in a homometallic Cr8 AF ring with an S=0 ground state. From the analysis of the spectra one can derive directly model independent values of the staggered nonuniform distribution of the local moment in the heterometallic ring Cr7Cd. The experimental values are found to be in excellent agreement with the theoretical values calculated on the basis of an effective spin Hamiltonian which includes crystal field effects.

Published
2006

44. Magnetization and spin dynamics of a Cr-based magnetic cluster

Author

Bianchi, A., primary, Carretta, S., additional, Santini, P., additional, Amoretti, G., additional, Furukawa, Y., additional, Kiuchi, K., additional, Ajiro, Y., additional, Narumi, Y., additional, Kindo, K., additional, Lago, J., additional, Micotti, E., additional, Arosio, P., additional, Lascialfari, A., additional, Borsa, F., additional, Timco, G., additional, and Winpenny, R.E.P., additional

Published
2010
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47. Synthesis and characterization of polyethylenimine-based iron oxide composites as novel contrast agents for MRI

Author

Masotti, A., primary, Pitta, A., additional, Ortaggi, G., additional, Corti, M., additional, Innocenti, C., additional, Lascialfari, A., additional, Marinone, M., additional, Marzola, P., additional, Daducci, A., additional, Sbarbati, A., additional, Micotti, E., additional, Orsini, F., additional, Poletti, G., additional, and Sangregorio, C., additional

Published
2008
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