Display omitted
•Number of amino acids derivatives in lipopeptide affects the properties of lipoplexes.•Lipoplexes behavior was examined within the cells in 2D and 3D models.•The amount of cationic ...groups in lipopeptide influences the lipoplex localization.•The highest transfection activity was observed for lipotripeptides.
Development of efficient biodegradable, environmentally responsive, biocompatible and non-toxic delivery system is needed for efficient gene delivery. As well known, properties of the vehicle are determined by the structure of carrier components. The aim of the current study was to estimate in vitro transfection efficacy of aliphatic di-, tri- and tetrapeptide-based cationic lipoplexes loaded with siRNA in function of a number of cationic groups using 2D (monolayer culture) and 3D (multicellular tumor spheroids) in vitro models. Physicochemical properties and cytotoxicity of the liposomes were found to be dependent upon a number of amino acid derivatives in an amphiphilic polar head. Uptake of liposomes loaded with nucleic acid (lipoplexes) and their localization in HEK293T cells was studied by confocal microscopy. The liposomes based on lipotripeptides had the highest transfection efficiency which was 20-fold higher than those fabricated from lipotetrapeptides.
In this paper, we discuss the results of applying a tagged neutron method for a remote nondestructive analysis of the elemental composition of matter on a conveyor. The tagged neutron method consists ...in irradiating the test substance with fast neutrons with an energy of 14 MeV, followed by recording the characteristic radiation of gamma quanta. Neutron tagging is carried out by an alpha detector built into the neutron generator.
Multiplicities of charged hadrons produced in deep inelastic muon scattering off a
6
LiD target have been measured as a function of the DIS variables
x
Bj
,
Q
2
,
W
2
and the final state hadron ...variables
p
T
and
z
. The
distributions are fitted with a single exponential function at low values of
to determine the dependence of
on
x
Bj
,
Q
2
,
W
2
and
z
. The
z
-dependence of
is shown to be a potential tool to extract the average intrinsic transverse momentum squared of partons,
, as a function of
x
Bj
and
Q
2
in a leading order QCD parton model.
.
Simulation results for future measurements of electromagnetic proton form factors at
P
¯
ANDA (FAIR) within the PandaRoot software framework are reported. The statistical precision with which the ...proton form factors can be determined is estimated. The signal channel
p
¯
p
→
e
+
e
-
is studied on the basis of two different but consistent procedures. The suppression of the main background channel,
i.e.
p
¯
p
→
π
+
π
-
, is studied. Furthermore, the background
versus
signal efficiency, statistical and systematical uncertainties on the extracted proton form factors are evaluated using two different procedures. The results are consistent with those of a previous simulation study using an older, simplified framework. However, a slightly better precision is achieved in the PandaRoot study in a large range of momentum transfer, assuming the nominal beam conditions and detector performance.
The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV mu + beam and a ...transversely polarised NH3 target. The Sivers asymmetry of the proton has been extracted in the Bjorken x range 0.003 0.03 . The asymmetry is different from zero and positive also in the low x region, where sea-quarks dominate. The kinematic dependence of the asymmetry has also been investigated and results are given for various intervals of hadron and virtual photon fractional energy. In contrast to the case of the Collins asymmetry, the results on the Sivers asymmetry suggest a strong dependence on the four-momentum transfer to the nucleon, in agreement with the most recent calculations.
The COMPASS Collaboration at CERN has measured the transverse spin azimuthal asymmetry of charged hadrons produced in semi-inclusive deep inelastic scattering using a 160 GeV mu + beam and a ...transversely polarised NH3 target. The Collins asymmetry of the proton was extracted in the Bjorken x range 0.003 < x < 0.7 . These new precise measurements confirm previous measurements from the COMPASS and HERMES Collaborations, which exhibit a definite effect in the valence quark region. The asymmetries for negative and positive hadrons are similar in magnitude and opposite in sign. They are compatible with model calculations in which the u-quark transversity is opposite in sign and somewhat larger than the d-quark transversity distribution function. The asymmetry is extracted as a function of Bjorken x, the relative hadron energy z and the hadron transverse momentum p T h . The high statistics and quality of the data also allow for more detailed investigations of the dependence on the kinematic variables. These studies confirm the leading-twist nature of the Collins asymmetry.
This document describes the technical layout and the expected performance of the Straw Tube Tracker (STT), the main tracking detector of the PANDA target spectrometer. The STT encloses a ...Micro-Vertex-Detector (MVD) for the inner tracking and is followed in beam direction by a set of GEM stations. The tasks of the STT are the measurement of the particle momentum from the reconstructed trajectory and the measurement of the specific energy loss for a particle identification. Dedicated simulations with full analysis studies of certain proton-antiproton reactions, identified as being benchmark tests for the whole PANDA scientific program, have been performed to test the STT layout and performance. The results are presented, and the time lines to construct the STT are described.
PDF
