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See detailNucleolus-associated bodies in meristematic cells of Pisum sativum
Jennane, A; Thiry, Marc ULg; Goessens, G

in Cell Biology International (1998), 22

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See detailThe nucleolus: structure/function relationship in RNA metabolism.
Hernandez-Verdun, Daniele; Roussel, Pascal; Thiry, Marc ULg et al

in Wiley Interdisciplinary Reviews. RNA (2010), 1(3), 415-31

The nucleolus is the ribosome factory of the cells. This is the nuclear domain where ribosomal RNAs are synthesized, processed, and assembled with ribosomal proteins. Here we describe the classical ... [more ▼]

The nucleolus is the ribosome factory of the cells. This is the nuclear domain where ribosomal RNAs are synthesized, processed, and assembled with ribosomal proteins. Here we describe the classical tripartite organization of the nucleolus in mammals, reflecting ribosomal gene transcription and pre-ribosomal RNA (pre-rRNA) processing efficiency: fibrillar center, dense fibrillar component, and granular component. We review the nucleolar organization across evolution from the bipartite organization in yeast to the tripartite organization in humans. We discuss the basic principles of nucleolar assembly and nucleolar structure/function relationship in RNA metabolism. The control of nucleolar assembly is presented as well as the role of pre-existing machineries and pre-rRNAs inherited from the previous cell cycle. In addition, nucleoli carry many essential extra ribosomal functions and are closely linked to cellular homeostasis and human health. The last part of this review presents recent advances in nucleolar dysfunctions in human pathology such as cancer and virus infections that modify the nucleolar organization. [less ▲]

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See detailThe nucleolus: When 2 became 3.
Thiry, Marc ULg; Lamaye, Françoise ULg; Lafontaine, Denis L. J.

in Nucleus (2011), 2(4),

Though the nucleolus is considered today as a multifunctional domain, its primary function is ribosome biogenesis. We have shown at the ultrastructural level that there are primarily two types of ... [more ▼]

Though the nucleolus is considered today as a multifunctional domain, its primary function is ribosome biogenesis. We have shown at the ultrastructural level that there are primarily two types of nucleolar organization: nucleoli containing three components in amniotes and two components in all other eukaryotes. In a recent report we made the additional, and surprising, finding that both types of nucleolar arrangement are found among living reptiles, viz. a bicompartmentalized nucleolus in turtles and a tricompartmentalized nucleolus in lizards, crocodiles and snakes. This latter organization occurs regardless of the species, the tissue or the developmental stages analyzed. These results are compatible with the view that the transition between bipartite and tripartite nucleoli coincided with the emergence of the amniotes within the Reptilia. They also support the previous hypothesis that turtles are primitive reptiles. The emergence in amniote vertebrates of a third nucleolar compartment might have imparted novel regulatory functions to the nucleolus, as well as perhaps, expanding the adaptability of ribosome synthesis to an ever changing environment, thus, enhancing the overall fitness of amniotic vertebrates. [less ▲]

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See detailNucleon nucleon interaction in a chiral constituent quark model
Bartz, Daniel ULg; Stancu, Floarea ULg

in Nuclear Physics A (2002), A699(1-2), 316-319

We study the nucleon-nucleon interaction within a chiral constituent quark model where the hyperfine interaction is due to pseudoscalar meson exchange. We calculate the S-3(1) and S-1(0) phase shifts by ... [more ▼]

We study the nucleon-nucleon interaction within a chiral constituent quark model where the hyperfine interaction is due to pseudoscalar meson exchange. We calculate the S-3(1) and S-1(0) phase shifts by using the resonating group method. Their behaviour clearly indicates the presence of a strong repulsive core at short distance. This is due to the spin-flavour symmetry of the interaction and to the quark interchange between the two interacting nucleons. We add a sigma-meson exchange quark-quark interaction which provides a medium range attraction necessary to describe the S-1(0) phase shift. We also explore the role of a tensor interaction at the quark level. [less ▲]

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See detailNucleon nucleon interaction in a chiral constituent quark model
Stancu, Floarea ULg; Pepin, S.; Glozman, L Ya

in Physical Review. C : Nuclear Physics (1997), C56

We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between ... [more ▼]

We study the short-range nucleon-nucleon interaction in a chiral constituent quark model by diagonalizing a Hamiltonian comprising a linear confinement and a Goldstone boson exchange interaction between quarks. The six-quark harmonic oscillator basis contains up to two excitation quanta. We show that the highly dominant configuration is $\mid s^4p^2[42]_O [51]_{FS}>$ due to its specific flavour-spin symmetry. Using the Born-Oppenheimer approximation we find a strong effective repulsion at zero separation between nucleons in both $^3S_1$ and $^1S_0$ channels. The symmetry structure of the highly dominant configuration implies the existence of a node in the S-wave relative motion wave function at short distances. The amplitude of the oscillation of the wave function at short range will be however strongly suppressed. We discuss the mechanism leading to the effective short-range repulsion within the chiral constituent quark model as compared to that related with the one-gluon exchange interaction. [less ▲]

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See detailNucleon nucleon scattering in a chiral constituent quark model
Bartz, Daniel ULg; Stancu, Floarea ULg

in Physical Review. C : Nuclear Physics (2001), C63

We study the nucleon-nucleon interaction in a chiral constituent quark model by using the resonating group method, convenient for treating the interaction between composite particles. The calculated phase ... [more ▼]

We study the nucleon-nucleon interaction in a chiral constituent quark model by using the resonating group method, convenient for treating the interaction between composite particles. The calculated phase shifts for the $^3S_1$ and $^1S_0$ channels show the presence of a strong repulsive core due to the combined effect of the quark interchange and the spin-flavour structure of the effective quark-quark interaction. Such a symmetry structure stems from the pseudoscalar meson exchange between the quarks and is a consequence of the spontaneous breaking of the chiral symmetry. We perform single and coupled channel calculations and show the role of coupling of the $\Delta\Delta$ and hidden color $CC$ channels on the behaviour of the phase shifts. [less ▲]

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See detailThe Nucleon-Nucleon Problem in Quark Models
Stancu, Floarea ULg

in Few-Body Systems (2003), 14

In the first part we summarize the status of the nucleon-nucleon (NN) problem in the context of Hamiltonian based constituent quark models and present results for the $\ell = 0$ phase shifts obtained from ... [more ▼]

In the first part we summarize the status of the nucleon-nucleon (NN) problem in the context of Hamiltonian based constituent quark models and present results for the $\ell = 0$ phase shifts obtained from the Goldstone-boson exchange model by applying the resonating group method. The second part deals with the construction of local shallow and deep equivalent potentials based on a Superymmetric Quantum Mechanics approach. [less ▲]

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See detailNucleon-Nucleus Potential at Low and Intermediate Energy in a Dirac-Hartree Model
Jaminon, Martine ULg; Mahaux, Claude ULg; Rochus, Pierre ULg

in Physical Review Letters (1979), 43

We calculate the average nucleon-nucleus potential from the Dirac-Hartree model, extended to positive energy. The sole input is a one-boson-exchange nucleon-nucleon interaction which reproduces ground ... [more ▼]

We calculate the average nucleon-nucleus potential from the Dirac-Hartree model, extended to positive energy. The sole input is a one-boson-exchange nucleon-nucleon interaction which reproduces ground-state properties. We obtain fair agreement with empirical values. Between 170 and 400 MeV, the calculated potential is repulsive in the nuclear interior but still attractive at the surface. This shape is related to the scalar and vector nature of the exchanged bosons. [less ▲]

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See detailNucleon-to-Pion Transition Distribution Amplitudes and Backward Electroproduction of Pions.
Pire, Bernard; Semenov-Tyan-Shanskiy, Kirill ULg; Szymanowski, Lech

in PoS - Proceedings of Science (2012), QNP2012

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See detailNucleon-to-pion transition distribution amplitudes: a challenge for PANDA
Pire, Bernard; Semenov-Tyan-Shanskiy, Kirill ULg; Szymanowski, Lech

in Few-Body Systems (2013)

Baryon-to-meson Transition Distribution Amplitudes (TDAs) appear as building blocks in the collinear factorized description of amplitudes for a class of hard exclusive reactions, prominent examples being ... [more ▼]

Baryon-to-meson Transition Distribution Amplitudes (TDAs) appear as building blocks in the collinear factorized description of amplitudes for a class of hard exclusive reactions, prominent examples being hard exclusive pion electroproduction off a nucleon in the backward region and baryon-antibaryon annihilation into a pion and a lepton pair or a charmonium. Baryon-to-meson TDAs extend both the concepts of generalized parton distributions (GPDs) and baryon distribution amplitudes (DAs) encoding valuable complementary information on the hadronic structure. We review the basic properties of baryon-to-meson TDAs and discuss the perspectives for the experimental access with the PANDA detector. [less ▲]

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See detailNUCLEOPHILIC ENANTIOSELECTIVE SYNTHESIS OF 6-[F-18]FLUORO-L-DOPA VIA 2 CHIRAL AUXILIARIES
Lemaire, Christian ULg; Plenevaux, Alain ULg; Cantineau, Robert et al

in Applied Radiation & Isotopes (1993), 44(4), 737-744

Asymmetric nucleophilic synthesis of 6-[F-18]fluoro-L-dopa was investigated in order to reach an enantiomeric excess of close to 100% of the L form of this amino acid. The radiochemical synthesis required ... [more ▼]

Asymmetric nucleophilic synthesis of 6-[F-18]fluoro-L-dopa was investigated in order to reach an enantiomeric excess of close to 100% of the L form of this amino acid. The radiochemical synthesis required [F-18]fluoride as fluorinating agent and regioselective nucleophilic substitution of commercially available 6-nitroveratraldehyde. The [F-18]fluorobenzaldehyde thus obtained was easily converted to the corresponding 2-[F-18]fluoro-4,5-dimethoxybenzyl bromide. This alkylating agent was added to the lithium enolates of 1-(S)-(-)camphor imine of t-butyl glycinate (1) and (S)-(-)- 1 -Boc-2-t-butyl-3-methyl-4-imidazolidinone [(S)- Boc-BMI] (2) in order to compare the enantiomeric excess of the L form obtained in each case with these two chiral inductors. The L-isomer of fluorodopa was isolated after H1 hydrolysis and HPLC purification in 5-10% radiochemical yield (decay corrected). The overall synthesis time was of 110 min. Through this synthetic pathway, the L-isomer of fluorodopa was obtained in 83% e.e with 1 and 96% e.e with 2 respectively, as determined by chiral HPLC. A practical three step preparative scale synthesis of 6-[F-19]fluoro-D,L-dopa is also presented. [less ▲]

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See detailNucleotidaktivierte Di- und Oligosaccharide sowie Verfahren zu deren Herstellung
Zervosen, Astrid ULg; Elling, Lothar; Nieder, Veronika et al

Patent (2003)

Detailed reference viewed: 5 (0 ULg)
See detailNucleotidaktivierte Di- und Oligosaccharide sowie Verfahren zu deren Herstellung
Zervosen, Astrid ULg; Elling, Lothar; Nieder, Veronika et al

Patent (2001)

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See detailNucleotide and Derived Amino Acid Sequence of the Subtilisin from the Antarctic Psychrotroph Bacillus Ta39
Narinx, E.; Davail, S.; Feller, Georges ULg et al

in Biochimica et Biophysica Acta (1992), 1131(1), 111-3

The nucleotide sequence of the subtilisin-encoding gene from the antarctic psychrotroph Bacillus TA39 was determined. The primary structure of the subtilisin precursor is composed of 420 amino acids ... [more ▼]

The nucleotide sequence of the subtilisin-encoding gene from the antarctic psychrotroph Bacillus TA39 was determined. The primary structure of the subtilisin precursor is composed of 420 amino acids giving rise to a mature enzyme of 309 amino acids. Asp-145, His-185 and Ser-361 are the proposed catalytic residues of the active site. [less ▲]

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See detailNucleotide sequence and amplification in bacteria of structural gene for rat growth hormone
Seeburg, P. H.; Shine, J.; Martial, Joseph ULg et al

in Nature (1977), 270(5637), 486-94

The primary structure of DNA containing the sequence for rat pituitary growth hormone mRNA has been determined. DNA was obtained by reverse transcription of polyadenylated RNA from cultured pituitary ... [more ▼]

The primary structure of DNA containing the sequence for rat pituitary growth hormone mRNA has been determined. DNA was obtained by reverse transcription of polyadenylated RNA from cultured pituitary cells and from recombinant bacterial plasmids. The amino acid sequences for rat growth hormone and its precursor form have been deduced from the determined nucleotide sequences. [less ▲]

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See detailNucleotide sequence and deduced primary structure of the Saccharomyces cerevisiae PUT4 proline permease gene.
Vandenbol, Micheline ULg; Jauniaux, J. C.; Grenson, M.

in Archives Internationales de Physiologie et de Biochimie (1988), 97

Detailed reference viewed: 2 (0 ULg)