Quick and Clean Cloning: A Ligation-Independent Cloning Strategy for Selective Cloning of Specific PCR Products from Non-Specific Mixes

We have developed an efficient strategy for cloning of PCR products that contain an unknown region flanked by a known sequence. As with ligation-independent cloning, the strategy is based on homology between sequences present in both the vector and the insert. However, in contrast to ligation-independent cloning, the cloning vector has homology with only one of the two primers used for amplification of the insert. The other side of the linearized cloning vector has homology with a sequence present in the insert, but nested and non-overlapping with the gene-specific primer used for amplification. Since only specific products contain this sequence, but none of the non-specific products, only specific products can be cloned. Cloning is performed using a one-step reaction that only requires incubation for 10 minutes at room temperature in the presence of T4 DNA polymerase to generate single-stranded extensions at the ends of the vector and insert. The reaction mix is then directly transformed into E. coli where the annealed vector-insert complex is repaired and ligated. We have tested this method, which we call quick and clean cloning (QC cloning), for cloning of the variable regions of immunoglobulins expressed in non-Hodgkin lymphoma tumor samples. This method can also be applied to identify the flanking sequence of DNA elements such as T-DNA or transposon insertions, or be used for cloning of any PCR product with high specificity

GRIDSA: femtosecond lifetime measurements with germanium detector arrays

We demonstrate the possibility to extract nuclear state femtosecond lifetimes from two-step $$\gamma$$ ray cascades measured with a Ge-detector array. The technique is based on measuring the Doppler shift of a $$\gamma$$ ray, caused by the recoil of a preceding $$\gamma$$ ray emission. Since the two $$\gamma$$ rays are populating/de-populating the same state they form a start/stop signal, the delay of which is compared to the slowing down motion of the nucleus within the target material. A multi-detector array combined with digital acquisition electronics in list mode, allows to measure several angular combinations and two-step cascades efficiently and simultaneously within one single experiment. The concept was demonstrated with the FIPPS array for the $$^{35}\hbox {Cl(n,}\gamma \hbox {)}^{36}\hbox {Cl}$$ reaction, where we obtained good agreement with literature values showing the validity of the method

Development of a liquid scintillator based active fission target for FIPPS

An active fission target has been developed for the FIPPS instrument at ILL, enabling for the first time an efficient suppression of \upbeta -delayed \upgamma rays in high-resolution and high-efficiency \upgamma -ray spectroscopy of fission fragments at a neutron beam. The target is based on a liquid scintillator in which the actinide is dissolved, resulting in a 4$$\pi$$ fragment detection. Measurements have been performed with $$^{233, 235}$$U, with a fission tagging efficiency of 97.8(25)%. The high efficiency, together with the good time resolution of the scintillator target, provide high-selectivity data for \upgamma -ray spectroscopy studies of fission fragments

Development of a gas filled magnet for FIPPS phase II

International audienceThe Fission Product Prompt γ-ray Spectrometer (FIPPS) is a new instrument of the Institut Laue-Langevin (ILL) for the spectroscopy of nuclei produced after neutron induced reactions. The future upgrade of the instrument aims to explore the neutron-rich region of the nuclear chart with higher selectivity by identifying the fragments produced after neutron induced fission. The Gas-Filled-Magnet (GFM) technique has been chosen in order to obtain a good mass separation (50 msr and P/P > 10%). A GFM design consisting of a 1/r magnetic field index and Thales circle-shaped entrance and exit magnet edges is proposed. The characteristic of the magnet is presented with realistic magnetic field calculations and Monte-Carlo simulations

Development of a gas filled magnet for FIPPS phase II

International audienceThe Fission Product Prompt γ-ray Spectrometer (FIPPS) is a new instrument of the Institut Laue-Langevin (ILL) for the spectroscopy of nuclei produced after neutron induced reactions. The future upgrade of the instrument aims to explore the neutron-rich region of the nuclear chart with higher selectivity by identifying the fragments produced after neutron induced fission. The Gas-Filled-Magnet (GFM) technique has been chosen in order to obtain a good mass separation (<4 amu at A = 150) and a large geometrical and momentum acceptance (>50 msr and P/P > 10%). A GFM design consisting of a 1/r magnetic field index and Thales circle-shaped entrance and exit magnet edges is proposed. The characteristic of the magnet is presented with realistic magnetic field calculations and Monte-Carlo simulations

High-precision spectroscopy of 65Ni via neutron capture

Detailed studies of the low-spin structures of neutron-rich Ni isotopes may help shedding light on the shape coexistence phenomenon. Of particular interest is the 65Ni nucleus, since it lies between 64Ni and 66Ni, where shape coexistence has been reported earlier. A spectroscopic investigation of 65Ni has been performed at Institut Laue-Langevin via the reaction64Ni(n,γ)65Ni, using the FIPPS HPGe array. Several new gamma transitions have been observed and angular correlation analyses have been performed. A comparison with Monte Carlo shell-model calculations pointed to a dominance of spherical states up to 1.5 MeV excitation energy, together with the appearance of two states of oblate character.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Detailed low-spin spectroscopy of Ni 65 via neutron capture reaction

An extended investigation of the low-spin structure of the Ni65 nucleus was performed at the Institut Laue-Langevin, Grenoble, France, via the neutron capture reaction Ni64(n,γ)Ni65, using the Fission Product Prompt Gamma-Ray Spectrometer High-Purity Ge array. The level scheme of Ni65 was significantly expanded, with two new levels and 87 newly found transitions. Angular correlation analyses were also performed, allowing us to assign spins and parities for a number of states and to determine multipolarity mixing ratios for selected γ transitions. The low-energy part of the experimental level scheme (up to about 1.4 MeV) was compared with Monte Carlo shell-model calculations, which predict spherical shapes for all states, apart from the 9/2+ and the second excited 1/2- states of oblate deformation.SCOPUS: ar.jinfo:eu-repo/semantics/publishe