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21.
22.
Miriam R. B. Porzberg Laust Moesgaard Catrine Johansson Udo Oppermann Jacob Kongsted Jasmin Mecinovi 《Molecules (Basel, Switzerland)》2022,27(3)
Epigenetic readout of the combinatorial posttranslational modification comprised of trimethyllysine and asymmetric dimethylarginine (H3K4me3R8me2a) takes place via biomolecular recognition of tandem Tudor-domain-containing protein Spindlin1. Through comparative thermodynamic data and molecular dynamics simulations, we sought to explore the binding scope of asymmetric dimethylarginine mimics by Spindlin1. Herein, we provide evidence that the biomolecular recognition of H3K4me2R8me2a is not significantly affected when R8me2a is replaced by dimethylarginine analogues, implying that the binding of K4me3 provides the major binding contribution. High-energy water molecules inside both aromatic cages of the ligand binding sites contribute to the reader–histone association upon displacement by histone peptide, with the K4me3 hydration site being lower in free energy due to a flip of Trp151. 相似文献
23.
FUNDAMENTALS OF TRANSMISSION FLUCTUATION SPECTROMETRY WITH VARIABLE SPATIAL AVERAGING 总被引:4,自引:0,他引:4
JianqiShen UlrichRiebel MarcusBreitenstein UdoKraeuter 《中国颗粒学报》2003,1(6):242-246
Transmission signal of radiation in suspension of particles performed with a high spatial and temporal resolution shows significant fluctuations,which are related to the physical properties of the particles and the process of spatial and temporal averaging.Exploiting this connection,it is possible to calculate the particle size distribution (PSD) and particle concentration.This paper provides an approach of transmission fluctuation spectrometry (TFS) with variable spatial averaging,The transmission fluctuations are expressed in terms of the expectancy of transmission square (ETS) and are obtained as a spectrum,which is a function of the variable beam diameter.The reversal point and the depth of the spectrum contain the information of particle size and particle concentration,respectively. 相似文献
24.
25.
Single molecule pulling experiments provide information about interactions in biomolecules that cannot be obtained by any other method. However, the reconstruction of the molecule's free energy profile from the experimental data is still a challenge, in particular, for the unstable barrier regions. We propose a new method for obtaining the full profile by introducing a periodic ramp and using Jarzynski's relation for obtaining equilibrium quantities from nonequilibrium data. Our simulated experiments show that this method delivers significant more accurate data than previous methods, under the constraint of equal experimental effort. 相似文献
26.
Niedermaier O Scheit H Bildstein V Boie H Fitting J von Hahn R Köck F Lauer M Pal UK Podlech H Repnow R Schwalm D Alvarez C Ames F Bollen G Emhofer S Habs D Kester O Lutter R Rudolph K Pasini M Thirolf PG Wolf BH Eberth J Gersch G Hess H Reiter P Thelen O Warr N Weisshaar D Aksouh F Van den Bergh P Van Duppen P Huyse M Ivanov O Mayet P Van de Walle J Aystö J Butler PA Cederkäll J Delahaye P Fynbo HO Fraile LM Forstner O Franchoo S Köster U Nilsson T Oinonen M Sieber T Wenander F Pantea M 《Physical review letters》2005,94(17):172501
We report on the first radioactive beam experiment performed at the recently commissioned REX-ISOLDE facility at CERN in conjunction with the highly efficient gamma spectrometer MINIBALL. Using 30Mg ions accelerated to an energy of 2.25 MeV/u together with a thin (nat)Ni target, Coulomb excitation of the first excited 2+ states of the projectile and target nuclei well below the Coulomb barrier was observed. From the measured relative deexcitation gamma-ray yields the B(E2;0(+)gs-->2(+)1) value of 30Mg was determined to be 241(31)e2 fm4. Our result is lower than values obtained at projectile fragmentation facilities using the intermediate-energy Coulomb excitation method, and confirms the theoretical conjecture that the neutron-rich magnesium isotope 30Mg resides outside the "island of inversion." 相似文献
27.
Papadakis CM Darko C Di Z Troll K Metwalli E Timmann A Reiter G Förster S 《The European physical journal. E, Soft matter》2011,34(1):7-8
We have found very slow crystallization in thin films of cylinder-forming poly(isoprene-b -ethyleneoxide) (P(I-b -EO)) diblock copolymers with PEO being the minority block. The film was crystallized at room temperature after melting at
62 °C . Imaging methods were combined with X-ray reflectometry and grazing-incidence small-angle X-ray scattering and diffraction.
Initially, hexagonally packed, amorphous PEO cylinders lie in the film plane. After 148 days, crystallized, finger-like terraces
were observed over the entire film surface. The terrace height is 20% higher than the repeat distance in the as-prepared film.
Thus, at the film surface, the cylinders have been destroyed by crystalline lamellae lying in the film plane. The PEO chain
stems are perpendicular to the substrate surface and are once-folded and fully interdigitated. The substrate-near layers still
consist of the hexagonally packed, amorphous PEO cylinders within the PI matrix. 相似文献
28.
Reiter P Khoo TL Lauritsen T Lister CJ Seweryniak D Sonzogni AA Ahmad I Amzal N Bhattacharyya P Butler PA Carpenter MP Chewter AJ Cizewski JA Davids CN Ding KY Fotiades N Greene JP Greenlees PT Heinz A Henning WF Herzberg R Janssens RV Jones GD Kondev FG Korten W Leino M 《Physical review letters》2000,84(16):3542-3545
The entry distribution in angular momentum and excitation energy for the formation of 254No has been measured after the 208Pb(48Ca,2n) reaction at 215 and 219 MeV. This nucleus is populated up to spin 22Planck's over 2pi and excitation energy greater, similar6 MeV above the yrast line, with the half-maximum points of the energy distributions at approximately 5 MeV for spins between 12Planck's over 2pi and 22Planck's over 2pi. This suggests that the fission barrier is greater, similar5 MeV and that the shell-correction energy persists to high spin. 相似文献
29.
We demonstrate a passively mode-locked femtosecond Yb:KLu(WO(4))(2) thin-disk laser oscillator. Chirped-pulse operation in the positive dispersion regime as well as solitary operation have been realized, and the laser performance of both configurations are compared. In the solitary mode-locking regime the output power exceeds 25 W in a diffraction-limited beam, and pulse durations as short as 440 fs at a 34.7 MHz repetition rate have been generated. For the first time we present a chirped-pulse operation of a thin-disk oscillator that yields a maximum average output power of 9.5 W with a Fourier limit of 450 fs. 相似文献
30.
At the new high flux reactor FRM-II in Munich the accelerator MAFF (Munich accelerator for fission fragments) is under design.
In the high neutron flux of 1014 n/cm2 s up to 1014 neutron-rich fission fragments per second are produced in the 1 g U-235 target. Ions with an energy of 30 keV are extracted
from the ion source. In the mass separator two isotopes can be selected. One of the beams is used for low energy experiments,
the other one is injected into an ECRIS (or EBIS) for charge breeding to a q/A≥0.16. A gas filled RFQ cooler is used for emittance improvement. The subsequent LINAC delivers beams with an energy ranging
from 3.7 MeV/u to 5.9 MeV/u. New IH structures are being developed at the Munich tandem laboratory. A small storage ring is
planned in a further stage to recycle the fission fragments. A thin target foil can be placed into this ring, e.g., for synthesis
of super-heavy elements. The through-going beam tube has been installed in the heavy water tank of the reactor. Tests of the
target ion source in a special oven to test long term stability and safety tests were in progress. 相似文献