13 research outputs found
Free Energy of PAMAM Dendrimer Adsorption onto Model Biological Membranes
We
investigated the thermodynamic, structural, and dynamics changes
in dendrimer–membrane systems during dendrimer adsorption to
biological membrane systems by combining atomistic molecular dynamics
simulations with umbrella sampling techniques to understand the atomistic
interactions between the dendrimer and biological membranes. An ethylenediamine
core polyamidoamine dendrimer (generation 3) with amine
terminal groups and both zwitterionic dipalmitoyl-phosphatidyl-choline
(DPPC) and anionic palmitoyl-oleoyl-phosphatidyl glycerol (POPG) lipid
bilayer membranes were used as the model dendrimer and biological
membranes, respectively, in this study. The free energy of the dendrimer
adsorption onto two model membranes with different charge states was
quantitatively determined. For the zwitterionic DPPC membrane, the
dendrimer has a minimum free energy of approximately 50 kcal/mol,
which is 15 kcal/mol higher than that observed in previous studies.
The dominant contribution to the adsorption potential energy is the
van der Waals attraction between the dendrimer and the DPPC membrane.
However, the anionic POPG membrane pulls the positively charged dendrimer
with an attractive mean force of about 200 pN, finally positioning
the dendrimer in the membrane headgroup region. As a result of these
strong attractive dendrimer and membrane interactions, the dendrimer
structurally undergoes the transition from spherical to a pancake
conformation, which slows its lateral mobility, especially in the
presence of the POPG membrane. The bilayer lipid membranes are also
perturbed by the dendrimer adsorption
Socioeconomic Disparities in the Prevalence of Blepharoptosis in the South Korean Adult Population Based on a Nationwide Cross-Sectional Study
Conformational properties of interacting neurofilaments: Monte Carlo simulations of cylindrically grafted apposing neurofilament brushes
Anticancer Activity of S-Allylmercapto-L-cysteine on Implanted Tumor of Human Gastric Cancer Cell
: (The African Mobile Finance Industrial Cooperation and Coordination between African Countries and South Korea: In Cases of Ghana and Uganda)
Measurement of the branching fractions for Cabibbo-suppressed decays and at Belle
International audienceWe present measurements of the branching fractions for the singly Cabibbo-suppressed decays and , and the doubly Cabibbo-suppressed decay , based on 980 of data recorded by the Belle experiment at the KEKB collider. We measure these modes relative to the Cabibbo-favored modes and . Our results for the ratios of branching fractions are , , and , where the uncertainties are statistical and systematic, respectively. The second value corresponds to , where is the Cabibbo angle; this value is larger than other measured ratios of branching fractions for a doubly Cabibbo-suppressed charm decay to a Cabibbo-favored decay. Multiplying these results by world average values for and yields , , and , where the third uncertainty is due to the branching fraction of the normalization mode. The first two results are consistent with, but more precise than, the current world averages. The last result is the first measurement of this branching fraction
Measurement of the production ratio in collisions at the resonance using decays at Belle
We measure the ratio of branching fractions for the decays to and using and samples, where stands for ( or ), with fb of data collected at the resonance with the Belle detector. We find the decay rate ratio of over to be , which is the most precise measurement to date. The first and second uncertainties are statistical and systematic, respectively, and the third uncertainty is systematic due to the assumption of isospin symmetry in
Measurement of branching fractions of and at Belle
We present a study of a singly Cabibbo-suppressed decay and a Cabibbo-favored decay based on 980 of data collected by the Belle detector, operating at the KEKB energy-asymmetric collider. We measure their branching fractions relative to : and . Combining with the world average , we have the absolute branching fractions: and . The first and second uncertainties are statistical and systematic, respectively, while the third ones arise from the uncertainty on . The mode is observed for the first time and has a statistical significance of . The branching fraction of has been measured with a threefold improvement in precision over previous results and is found to be consistent with the world average
Test of light-lepton universality in decays with the Belle II experiment
International audienceWe present a measurement of the ratio of branching fractions of the lepton decaying to muons or electrons using data collected with the Belle II detector at the SuperKEKB collider. The sample has an integrated luminosity of 362 fb at a centre-of-mass energy of 10.58 GeV. Using an optimised event selection, a binned maximum likelihood fit is performed using the momentum spectra of the electron and muon candidates. The result, , where the first uncertainty is statistical and the second is systematic, is the most precise to date. It provides a stringent test of the light-lepton universality, translating to a ratio of the couplings of the muon and electron to the boson in decays of , in agreement with the standard model expectation of unity