The differential cross sections for the yields of nuclear fragments at an angle of 3.5◦ in the fragmentation of carbon nuclei with energy 0.95 GeV per nucleon on a beryllium target were measured in ...the FRAGM experiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of fragments were used to test the following four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD. For light fragments, the slope parameters of the kinetic-energy spectra were obtained in the cumulative region.
SWI2/SNF2 chromatin-remodeling proteins mediate the mobilization of nucleosomes and other DNA-associated proteins. SWI2/SNF2 proteins contain sequence motifs characteristic of SF2 helicases but do ...not have helicase activity. Instead, they couple ATP hydrolysis with the generation of superhelical torsion in DNA. The structure of the nucleosome-remodeling domain of zebrafish Rad54, a protein involved in Rad51-mediated homologous recombination, reveals that the core of the SWI2/SNF2 enzymes consist of two alpha/beta-lobes similar to SF2 helicases. The Rad54 helicase lobes contain insertions that form two helical domains, one within each lobe. These insertions contain SWI2/SNF2-specific sequence motifs likely to be central to SWI2/SNF2 function. A broad cleft formed by the two lobes and flanked by the helical insertions contains residues conserved in SWI2/SNF2 proteins and motifs implicated in DNA-binding by SF2 helicases. The Rad54 structure suggests that SWI2/SNF2 proteins use a mechanism analogous to helicases to translocate on dsDNA.
The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of
T
0
= 0.6 GeV per nucleon on a berylliumtarget were measured in ...the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD.
Momentum spectra of all long lived fragments from 12C fragmentation at 3.5o on different targets have been measured. Obtained fragmentation peak widths are compared with predictions of statistical ...model. An independence of these widths from target nuclei has been checked with high precision.
Momentum spectra of all long-lived fragments from 12C fragmentation at 3.5° have been measured. Differential cross sections span up to five orders of its magnitude. The preliminary results are ...compared with predictions of two transport codes: INCL++ and LAQGSM03.03. Both models give a good description of the data except few items which are discussed.
The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/c π^{-} beam and a transversely polarized ...ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/c^{2} and 8.5 GeV/c^{2}. Within the experimental uncertainties, the observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of quantum chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was obtained at a hard scale comparable to that of these DY results. This opens the way for possible tests of fundamental QCD universality predictions.
The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T{sub 0} = 0.6 GeV per nucleon on a berylliumtarget were measured ...in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion–ion interactions: BC, INCL++, LAQGSM03.03, and QMD.
Measurements of the Collins and Sivers asymmetries for charged pions and charged and neutral kaons produced in semi-inclusive deep-inelastic scattering of high energy muons off transversely polarised ...protons are presented. The results were obtained using all the available COMPASS proton data, which were taken in the years 2007 and 2010. The Collins asymmetries exhibit in the valence region a non-zero signal for pions and there are hints of non-zero signal also for kaons. The Sivers asymmetries are found to be positive for positive pions and kaons and compatible with zero otherwise.
Intercalated compound of graphite fluoride with n-heptane has been synthesized at room temperature using a multi-stage process including fluorination by a gaseous BrF3 and a set of intercalant ...exchange reactions. It was found that composition of the compound is CF0.40(C7H16)0.04 and the guest molecules interact with the graphite fluoride layers through the van der Waals forces. Since the distance between the filled layers is 1.04nm and the unfilled layers are separated by ∼0.60nm, the obtained compound can be considered as a stack of the fluorinated graphenes. These fluorinated graphenes are large in area making it possible to study local destruction of the π conjugated system on the basal plane. It was shown that fluorine atoms form short chains, while non-fluorinated sp2 carbon atoms are organized in very narrow ribbons and aromatic areas with a size smaller than 3nm. These π electron nanochains and nanoislands preserved after the fluorination process are likely responsible for the value of the energy gap of the compound of ∼2.5eV. Variation in the size and the shape of π electron regions within the fluorinated graphene layers could be a way for tuning the electronic and optical characteristics of the graphene-based materials.
Insider report: A fluoroleucine mutant of ubiquitin (cyan) with two strategically placed fluorine reporter groups in its core was synthesised. 1H NMR, crystallography, CD spectroscopy, biological ...assay and calorimetry indicate minimal structural and functional perturbation compared to the native protein (yellow; see picture). 19F NMR spectra indicate changes within the core during folding and unfolding.
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