| 1. |
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| 2. |
- Döring, J., et al.
(författare)
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Band terminations in the valence space of 86Zr
- 2000
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Ingår i: Physical Review C - Nuclear Physics. - 0556-2813. ; 61:3, s. 343101-343106
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in 86Zr up to 30+ and 27- were observed via the 58Ni(32S,4p) reaction at 135 MeV beam energy using the combined GAMMASPHERE and MICROBALL systems. Calculations performed with the configuration-dependent shell-correction approach show that these states are built from six g9/2 neutrons and at most four protons excited from the p1/2,p3/2,f5/2 subshells to the g9/2 subshell at small deformation. The highest observed states at 27- and 30+ are interpreted as band-terminating states with the latter having the highest spin available in the valence space for 86Zr.
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| 3. |
- Rudolph, Dirk, et al.
(författare)
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Shell-model Influence in the Rotational Nucleus 86Mo
- 1996
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 54:1, s. 117-124
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Mo-86 were studied by means of the fusion evaporation reaction Ni-58(S-32,2p2n) Mo-86 at 135 MeV beam energy. Charged-particle-gamma gamma and -gamma gamma gamma coincidences recorded with the early implementation of the GAMMASPHERE array and the MICROBALL charged-particle detection system were used to largely extend the level scheme of the T-tau=1 nucleus Mo-86 to a possible spin of I=24h at 13 MeV excitation energy. The excitation scheme is compared to neighboring nuclei. There is evidence for enhanced shell-model influence in the 4 quasiparticle region (I=12-16h). The observed (pi=+,alpha=0) sequence at spin I greater than or equal to 16 h appears to be associated with a triaxial collective rotational band. This interpretation is supported by calculations within the configuration-dependent shell-correction approach with the cranked Nilsson potential.
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| 4. |
- Sun, H., et al.
(författare)
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New Band Structures and an Unpaired Crossing in 78Kr
- 1999
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 59:2, s. 655-664
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Kr-78 were studied using the Ni-58(Na-23,3p) reaction at 70 MeV and the Ni-58(Si-23,alpha 4p) reaction at 130 MeV. Prompt gamma-gamma coincidences were measured using the Pitt-FSU detector array and the GAMMASPHERE-MICROBALL array. Results from these experiments have led to 26 new excitation levels, some of which have been grouped into 3 new bands. Spins were assigned based on directional correlations of oriented nuclei. Two of the new negative-parity bands appear to form a signature-partner pair based on a two-quasineutron structure, in contrast to the previously known two-quasiproton negative-parity bands. A forking has been observed at the 24(+) state in the yrast band, which calculations suggest may result from an unpaired crossing. The available evidence suggests oblate shapes in the yrast band coexist with prolate shapes in the negative-parity bands. [S0556-2813(99)04602-6].
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| 5. |
- Sylvan, G N, et al.
(författare)
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Deformation driving intruder orbitals in Kr-77
- 1997
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 56:2, s. 772-781
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Kr-77 were identified via analysis of prompt gamma-gamma coincidences in the Ni-58(Si-29,2 alpha 2p) reaction at 128 MeV at the Gammasphere facility. Evaporation channel selection was achieved using the 95 element Microball charged-particle detector. 27 new states and 42 new transitions were found, The positive-parity bands were confirmed and the alpha=-1/2 band extended to 39/2(+). The negative-parity signature pair was extended to 31/2(-) and 37/2(-). Two new high-lying negative-parity bands were found extending from a state of spin I = 15/2 and energy 2.6 MeV to 17.4 MeV at I = (55/2). The new bands appear highly deformed and become yrast at high spin. A three-quasiparticle structure based on deformation driving, low-K unique-parity and intruder orbitals is suggested for them.
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| 6. |
- Lerma, F., et al.
(författare)
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Superdeformed bands in Sr80-83, Y82-84, Zr-83,Zr-84 : Transition quadrupole moments, moments of inertia, and configuration assignments
- 2003
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Ingår i: Physical Review C. Nuclear Physics. - 0556-2813 .- 1089-490X. ; 67:4, s. 044310-
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Tidskriftsartikel (refereegranskat)abstract
- Multiple superdeformed bands in the nuclei Sr80-83, Y82-84, and Zr-83,Zr-84 have been studied in a backed-target experiment, using the Gammasphere and the Microball 4pi detector arrays. For 15 bands in these nuclei, average transition quadrupole moments have been measured with high accuracy, using the Doppler-shift attenuation method. Among these are the newly observed superdeformed bands in Y-83,Y-84, which are isospectral with the bands in Sr-82,Sr-83. These isospectral bands have nearly identical transition quadrupole moments. Two of the bands in Sr-81 interact and cross transitions between them are observed. The present measurements place stringent conditions on configuration assignments for the bands obtained from two types of mean-field calculations, leading to a consistent understanding of the mass similar to80 superdeformed bands. The assignments for different bands arise from one or more nucleons occupying the N-0=5h(11/2) intruder orbital.
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| 7. |
- Cardona, R., et al.
(författare)
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High-spin structure of normal-deformed bands in 84Zr
- 2003
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Ingår i: Physical Review C - Nuclear Physics. - 0556-2813. ; 68, s. 1-024303
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Tidskriftsartikel (refereegranskat)abstract
- The reaction 58Ni(32S, α2p) at E lab= 135 MeV was used to populate high-spin states in 84Zr. The complete GAMMASPHERE and MICROBALL arrays were used to obtain clean γ- γ- γ line shapes to be analyzed by the Doppler shift attenuation method and to determine 27 lifetimes in the ground-state band and in two excited bands. Side-feeding times were also measured by comparing the line shapes gated with transitions above and below the state under study. The deduced electric quadrupole moments for the ground-state band are consistent with a very slow reduction with frequency with values ranging between 2.4(3) and 2.0(1)e b. The negative-parity bands feature also an approximate constancy of quadrupole moment with values similar to those in the ground-state band. Cranking calculations agree with this behavior in both parity bands and suggest an interpretation of the upper states in the ground-state band as part of a very slowly terminating band. Shell-dependent cranked Nilsson calculations explain a fourth γ cascade as pertaining to a noncollective structure terminating at I = 20+.
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| 8. |
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| 9. |
- Wiedeking, M., et al.
(författare)
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Transition strengths and band terminations in 86Zr
- 2003
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Ingår i: Physical Review C - Nuclear Physics. - 0556-2813. ; 67, s. 1-034320
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Tidskriftsartikel (refereegranskat)abstract
- High angular momentum states in 86Zr were populated through the 58Ni(32S,4p) reaction at 135 MeV using the 88-In. Cyclotron at Lawrence Berkeley National Laboratory. Recoiling 86Zr nuclei were stopped in a thick Ta backing. Prompt multi-γ coincidences with evaporated charged particles were detected using the full array of GAMMASPHERE and the MICROBALL. Mean lifetimes of 36 levels in 86Zr were measured using the Doppler-shift attenuation method. Transition quadrupole moments Qt were found in the range of about 0.3-1.5 e b in the positive-parity bands. The negative-parity bands show Qt values from about 0.25 to 1.2 e b. In the yrast positive-parity band, a sharp drop in collectivity approaching the 30+ state supports the interpretation of band termination in this configuration. Decreasing Qt values approaching the 24+ and 27- states also provide an indication of terminating structures.
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| 10. |
- Cooper, M. W., et al.
(författare)
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New γ transitions in 27Na from 14C on 14C
- 2001
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Ingår i: Nuclear Physics A. - 0375-9474. ; 682:1-4, s. 131-135
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Tidskriftsartikel (refereegranskat)abstract
- The neutron rich 27Na was studied at Florida State University using the 14C(14C,p) reaction at 22 MeV. The 14C target was 0.28 mg/cm2 thick. γ-γ and particle-γ, coincidences were measured using 2 four-crystal clover detectors, 7 Compton-suppressed HPGe detectors, and a particle detector telescope at 0°. The 1757, 1823, and 2219 keV transitions are likely yrast transitions in 27Na. Based on systematics of neighboring nuclei, the first two lines probably arise from the decays of the 7/2+ and 9/2+ states. The results will be discussed in terms of both the shell model and the cranked Nilsson-Strutinsky rotational model.
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| 11. |
- CRISTANCHO, F, et al.
(författare)
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MULTIPLE SUPERDEFORMED BANDS IN SR-81
- 1995
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Ingår i: Physics Letters B. - 0370-2693 .- 1873-2445. ; 357:3, s. 281-286
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Tidskriftsartikel (refereegranskat)abstract
- Four superdeformed bands extending over five to twelve transitions have been identified in Sr-81 from a study With the Gammasphere array and the Microball charged-particle array, One of the bands shows an upbend in the dynamic moment of inertia at a rotational frequency of 1.2 MeV and all bands exhibit a nearly constant moment of inertia below that frequency.
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| 12. |
- Dickman, Rachael, et al.
(författare)
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A Chemical Biology Approach to Understanding Molecular Recognition of Lipid II by Nisin(1–12): Synthesis and NMR Ensemble Analysis of Nisin(1–12) and Analogues
- 2019
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Ingår i: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 25:64, s. 14572-14582
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Tidskriftsartikel (refereegranskat)abstract
- © 2019 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. Natural products that target lipid II, such as the lantibiotic nisin, are strategically important in the development of new antibacterial agents to combat the rise of antimicrobial resistance. Understanding the structural factors that govern the highly selective molecular recognition of lipid II by the N-terminal region of nisin, nisin(1–12), is a crucial step in exploiting the potential of such compounds. In order to elucidate the relationships between amino acid sequence and conformation of this bicyclic peptide fragment, we have used solid-phase peptide synthesis to prepare two novel analogues of nisin(1–12) in which the dehydro residues have been replaced. We have carried out an NMR ensemble analysis of one of these analogues and of the wild-type nisin(1–12) peptide in order to compare the conformations of these two bicyclic peptides. Our analysis has shown the effects of residue mutation on ring conformation. We have also demonstrated that the individual rings of nisin(1–12) are pre-organised to an extent for binding to the pyrophosphate group of lipid II, with a high degree of flexibility exhibited in the central amide bond joining the two rings.
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| 13. |
- Hobbins, John C., et al.
(författare)
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Antibiotic prophylaxis before amniocentesis
- 2011
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Ingår i: Prenatal Diagnosis. - : Wiley. - 1097-0223 .- 0197-3851. ; 31:12, s. 1213-1214
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 14. |
- Longo, Francesco, et al.
(författare)
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Cell-type-specific disruption of cortico-striatal circuitry drives repetitive patterns of behavior in fragile X syndrome model mice.
- 2023
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Ingår i: Cell reports. - 2211-1247. ; 42:8
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Tidskriftsartikel (refereegranskat)abstract
- Individuals with fragile X syndrome (FXS) are frequently diagnosed with autism spectrum disorder (ASD), including increased risk for restricted and repetitive behaviors (RRBs). Consistent with observations in humans, FXS model mice display distinct RRBs and hyperactivity that are consistent with dysfunctional cortico-striatal circuits, an area relatively unexplored in FXS. Using a multidisciplinary approach, we dissect the contribution of two populations of striatal medium spiny neurons (SPNs) in the expression of RRBs in FXS model mice. Here, we report that dysregulated protein synthesis at cortico-striatal synapses is a molecular culprit of the synaptic and ASD-associated motor phenotypes displayed by FXS model mice. Cell-type-specific translational profiling of the FXS mouse striatum reveals differentially translated mRNAs, providing critical information concerning potential therapeutic targets. Our findings uncover a cell-type-specific impact of the loss of fragile X messenger ribonucleoprotein (FMRP) on translation and the sequence of neuronal events in the striatum that drive RRBs in FXS.
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| 15. |
- Rodriguez, W., et al.
(författare)
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High spin states of the normally deformed bands of y 83
- 2019
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Ingår i: Physical Review C. - 2469-9985. ; 100:2
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Tidskriftsartikel (refereegranskat)abstract
- Level lifetime and side-feeding time measurements were performed on the excited states of the normally deformed bands of Y83 using the Doppler-shift attenuation method (DSAM). The high spin states of Y83 were populated using the fusion-evaporation reaction Ni58(S32,α3p)Y83 at 135 MeV. Twenty-two level lifetime and side-feeding times were determined in most of the cases by comparing the line shapes gated with transitions above and below the state under study. Quadrupole moments determined from lifetime measurements are in the range 1.1-3.1 eb, and are similar to the ones found for some of the neighboring nuclei. The measured side-feeding times were compared with predictions made by simulations carried out with the Gammapace code. The results were in agreement with the experimental values by assuming reduced transition probabilities of the collective transitions in the continuum region, lying in the range 40-80 W.u. The discrete excited states were studied with paired cranked Nilsson-Strutinsky-Bogoliubov (CNSB) calculations carried out for the first time for an A≈80 nucleus. Unpaired cranked Nilsson-Strutinsky (CNS) calculations were used to specify configurations and study the band crossings. The measured |Qt| values show a general agreement with CNSB calculations. Cranked shell model analysis evinced that the smallest quadrupole moment appears at the sharpest band crossing of the bands studied and CNSB calculations show an increase of the deformation thereinafter.
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| 16. |
- Sperling, L, et al.
(författare)
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How to identify twins at low risk of spontaneous preterm delivery
- 2005
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Ingår i: Ultrasound in Obstetrics & Gynecology. - : Wiley. - 1469-0705 .- 0960-7692. ; 26:2, s. 138-144
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Tidskriftsartikel (refereegranskat)abstract
- Objective The aim of this study was to evaluate transvaginal sonograpbic assessment of cervical length at 23 weeks as a screening test for spontaneous preterm delivery in order to define a cut-off value that could be used to select twin pregnancies at low risk of spontaneous preterm delivery. Methods In a prospective multicenter study of 383 twin pregnancies included before 14 + 6 weeks a cervical scan with measurement of the cervical length was performed at 23 weeks' gestation. The results were blinded for the clinicians if the cervical length was >= 15 mm. The rates of spontaneous delivery at different cut-off levels of cervical length were determined. Results Eighty-nine percent of the twins had dichorionic placentation and 58% were conceived after assisted reproduction. The rate of spontaneous preterm delivery was 2.3% (1.5% for dichorionic (DC) and 9.1% for (MC) monochorionic twins) before 28 weeks and 18.5% (17.1% for DC and 29.5% for MC twins) before 35 weeks. The screen-positive rate was 5% for a cervical length <= 20, 7-8% at <= 25, 16-17% at <= 30 and 34-48% at <= 35mm depending on chorionicity. The false-negative rate (1 - negative predictive value) ranged from 1.2% at 28 weeks to 18.6% at 35 weeks for all twins. Receiver-operating characteristics curves showed that the sensitivity increased with declining gestation I age with cut-off levels of highest accuracy at 21 mm for 28 weeks and 29 mm for 33 weeks. Conclusions Cervical length measurement at 23 weeks of gestation is a good screening test for predicting twins at low risk of preterm and very preterm delivery, especially in DC twins. The present results suggest that a cut-off of 25 mm should be recommended.
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| 17. |
- Tabor, S. L., et al.
(författare)
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Structure of neutron-rich s-d shell nuclei
- 2002
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Ingår i: Physics of Atomic Nuclei. - : Pleiades Publishing Ltd. - 1063-7788 .- 1562-692X. ; 65:4, s. 713-719
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Tidskriftsartikel (refereegranskat)abstract
- States in neutron-rich s-d shell nuclei were populated in the reaction of a 14C beam at Elab = 22 MeV on a 14C target. Coincidences between γ rays and either other γ rays or light charged particles were measured. γ rays in coincidence with protons established levels at 66.8, 1730, 1823, and 2219 keV in 27Na. The states are compared with calculations based on the s-d shell model and the cranked Nilsson-Strutinsky model. A number of levels in 24Ne were observed in both α-γ and α-γ-γ coincidences and are compared with shell-model calculations.
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