221 research outputs found

    How does the elastic scattering of 12C + 20Ne compare with that of 16O + 16O ?

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    Excitation functions for 5 exit channels of the 12C + 20Ne system are given in the range 22-28 MeV centre of mass incident energy. An important structure is observed in the elastic scattering excitation functions taken at 90° and 130° (C.M.). This structure, which reminds one of the 16O + 16O case, is studied in terms of angular momentum matching. An angular distribution taken at 24.7 MeV (C.M.) is also presented. The direct channel absorption is shown to be intermediate between the 16O + 16O and 18O + 18O cases

    DISTRIBUTIONS ISOTOPIQUES DES PRODUITS DE TRANSFERTS TRÈS INÉLASTIQUES ENTRE IONS LOURDS

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    On compare les distributions isotopiques expérimentales des produits de transfert trÚs inélastiques obtenus par les réactions 40Ca (284 MeV) + 40Ca et 40Ar (295 MeV) + 232Th

    Plate-Boundary Kinematics of the Afrera Linkage Zone (Afar) From InSAR and Seismicity

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    International audienceStudying the mechanisms of interaction between rift segments is key to understanding the kinematics of plate boundaries in continental rifts. However, the spatial and temporal evolution of deformation at rift linkage zones is rarely observed directly. Here, we combine InSAR data spanning 2005–2010 and 2014–2019 from ENVISAT and Sentinel-1 satellites, respectively, with local seismicity from the Afar rift to investigate the plate-boundary kinematics of the Afrera linkage zone, the junction between the Erta Ale and Tat Ali magmatic segments in Northern Afar (Ethiopia). We obtain time-series of cumulative InSAR Line-Of-Sight (LOS) displacements that show deformation is accommodated by a series of active en-echelon faults striking ∌NS and characterized by normal slip associated with a left-lateral strike-slip component. Additionally, we observe spatial variation in fault behavior with stick-slip and creep. The faults in the center of the linkage zone behave primarily in a stick-slip mode (with abrupt fault displacements up to ∌40 mm) and fault motions are associated with earthquakes of ML > 5. Conversely, faults at the edge of the linkage zone, near the magmatic segments, show creep and some stick-slip behavior (with cumulative LOS displacement up to ∌30–40 mm over a ∌5-year period) accompanied by low-level seismicity. Some of the creeping faults are also spatially associated with hydrothermal springs. We interpret that the temporal behavior of the faults in the linkage zone is controlled by the interplay between tectonic extension, high heat flows, and fluid circulation near the magmatic segments where creeping of some faults is favored

    Precision mass measurements of very short-lived, neutron-rich Na isotopes using a radiofrequency spectrometer

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    Mass measurements of high precision have been performed on sodium isotopes out to 30^{30}Na using a new technique of radiofrequency excitation of ion trajectories in a homogeneous magnetic field. This method, especially suited to very short-lived nuclides, has allowed us to significantly reduce the uncertainty in mass of the most exotic Na isotopes: a relative error of 5x10−7^{-7} was achieved for 28^{28}Na having a half-life of only 30.5 ms and 9x10−7^{-7} for the weakly produced 30^{30}Na. Verifying and minimizing binding energy uncertainties in this region of the nuclear chart is important for clarification of a long standing problem concerning the strength of the NN=20 magic shell closure. These results are the fruit of the commissioning of the new experimental program Mistral

    Accurate mass measurements of short-lived isotopes with the MISTRAL rf spectrometer

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    The MISTRAL experiment has measured its first masses at ISOLDE. Installed in May 1997, this radiofrequency transmission spectrometer is to concentrate on nuclides with particularly short half-lives. MISTRAL received its first stable beam in October and first radioactive beam in November 1997. These first tests, with a plasma ion source, resulted in excellent isobaric separation and reasonable transmission. Further testing and development enabled first data taking in July 1998 on neutron-rich Na isotopes having half-lives as short as 31 ms

    ATP-binding cassette (ABC) transporters in normal and pathological lung

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    ATP-binding cassette (ABC) transporters are a family of transmembrane proteins that can transport a wide variety of substrates across biological membranes in an energy-dependent manner. Many ABC transporters such as P-glycoprotein (P-gp), multidrug resistance-associated protein 1 (MRP1) and breast cancer resistance protein (BCRP) are highly expressed in bronchial epithelium. This review aims to give new insights in the possible functions of ABC molecules in the lung in view of their expression in different cell types. Furthermore, their role in protection against noxious compounds, e.g. air pollutants and cigarette smoke components, will be discussed as well as the (mal)function in normal and pathological lung. Several pulmonary drugs are substrates for ABC transporters and therefore, the delivery of these drugs to the site of action may be highly dependent on the presence and activity of many ABC transporters in several cell types. Three ABC transporters are known to play an important role in lung functioning. Mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene can cause cystic fibrosis, and mutations in ABCA1 and ABCA3 are responsible for respectively Tangier disease and fatal surfactant deficiency. The role of altered function of ABC transporters in highly prevalent pulmonary diseases such as asthma or chronic obstructive pulmonary disease (COPD) have hardly been investigated so far. We especially focused on polymorphisms, knock-out mice models and in vitro results of pulmonary research. Insight in the function of ABC transporters in the lung may open new ways to facilitate treatment of lung diseases
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