Hybrid approach to calculating proton stopping power in hydrogen

Proton stopping power in hydrogen is calculated using a hybrid method. A two-centre convergent close-coupling method is used for calculations involving the proton fraction of the beam, while the Born approximation is used for the hydrogen fraction. For proton-hydrogen collisions rearrangement processes are explicitly included via a two-centre expansion. Hydrogen-hydrogen collisions are calculated including one- and two-electron processes. Despite using the first-order approximation in the hydrogen-hydrogen channel, overall reasonably good agreement with experiment is seen above 100 keV. © Published under licence by IOP Publishing Ltd

Close-coupling approach to antiproton-impact ionisation of H2 with analytical spherical averaging

Integrated cross section for single ionisation of molecular hydrogen by antiproton impact has been calculated in a wide range of impact energies from 1 keV up to 2 MeV using a close-coupling approach. For the first time all possible orientations of the molecular target have been accounted for using an ab initio analytical spherical averaging technique. Obtained results are in good agreement with experiment

Fully quantum-mechanical treatment of proton-hydrogen scattering

© Published under licence by IOP Publishing Ltd. A fully quantum-mechanical convergent close-coupling approach to proton collisions with atomic hydrogen has been developed. Cross sections for target ionisation and electron capture by the projectile have been calculated in the energy range from 20 keV to 1 MeV. Calculated electron capture cross sections are in good agreement with the experiment, however for ionisation discrepancies between theory and experiment at intermediate energies still remain

Ionisation of noble gas atoms and H2O by antiproton impact

© Published under licence by IOP Publishing Ltd. A time-dependent convergent close-coupling approach to antiproton collisions with noble gas atoms and H2O has been developed using a fully multielectron treatment of the targets. Integrated cross sections for single ionisation have been calculated in a wide range of impact energies from 5 keV up to 2 MeV. Obtained results are in good agreement with experiment

Calculation of antihydrogen formation via antiproton scattering with excited positronium

Detailed presentation of results shown in the ealrier Phys. Rev. Lett. (114, 183201, (2015)).Shows all partial cross sections for antihydrogen formation in collisions of antiprotons with positronium in quantum states n = 1-3

The Hilbert-Schmidt Theorem Formulation of the R-Matrix Theory

Using the Hilbert-Schmidt theorem, we reformulate the R-matrix theory in terms of a uniformly and absolutely convergent expansion. Term by term differentiation is possible with this expansion in the neighborhood of the surface. Methods for improving the convergence are discussed when the R-function series is truncated for practical applications.Comment: 16 pages, Late

Deuteron and antideuteron production in Au+Au collisions at sqrt(s_NN)=200 GeV

The production of deuterons and antideuterons in the transverse momentum range 1.1 < p_T < 4.3 GeV/c at mid-rapidity in Au + Au collisions at sqrt(s_NN)=200 GeV has been studied by the PHENIX experiment at RHIC. A coalescence analysis comparing the deuteron and antideuteron spectra with those of protons and antiprotons, has been performed. The coalescence probability is equal for both deuterons and antideuterons and increases as a function of p_T, which is consistent with an expanding collision zone. Comparing (anti)proton yields p_bar/p = 0.73 +/- 0.01, with (anti)deuteron yields: d_bar/d = 0.47 +/- 0.03, we estimate that n_bar/n = 0.64 +/- 0.04.Comment: 326 authors, 6 pages text, 5 figures, 1 Table. Submitted to PRL. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

Pharmacological targeting of MTHFD2 suppresses acute myeloid leukemia by inducing thymidine depletion and replication stress

The folate metabolism enzyme MTHFD2 (methylenetetrahydrofolate dehydrogenase/cyclohydrolase) is consistently overexpressed in cancer but its roles are not fully characterized, and current candidate inhibitors have limited potency for clinical development. In the present study, we demonstrate a role for MTHFD2 in DNA replication and genomic stability in cancer cells, and perform a drug screen to identify potent and selective nanomolar MTHFD2 inhibitors; protein cocrystal structures demonstrated binding to the active site of MTHFD2 and target engagement. MTHFD2 inhibitors reduced replication fork speed and induced replication stress followed by S-phase arrest and apoptosis of acute myeloid leukemia cells in vitro and in vivo, with a therapeutic window spanning four orders of magnitude compared with nontumorigenic cells. Mechanistically, MTHFD2 inhibitors prevented thymidine production leading to misincorporation of uracil into DNA and replication stress. Overall, these results demonstrate a functional link between MTHFD2-dependent cancer metabolism and replication stress that can be exploited therapeutically with this new class of inhibitors

Fully quantal close-coupling approach to antiproton-hydrogen collisions

A fully quantal close-coupling integral-equation approach to antiproton-hydrogen collisions has been developed. Integral and fully differential cross sections have been calculated

WATER AND POWER PRODUCTIVITY OF GRAPE PRODUCTION IN FERGANA VALLEY

The study was carried out in 2013-2014 at two pilot farms of Fergana Valley cultivating grapevines using canal irrigation and groundwater. The farm data on irrigation applications and power inputs were compared with the experience of farmers in Turkey and Iran. The study indicated that at the farm where the groundwater was used in irrigation the yield of grapes was 2.7 times and water productivity 3 times higher as compared to using canal irrigation. This was found to be the consequence of inadequate applications of organic fertilizers and farming machinery, and poor irrigation scheduling under canal irrigation. The use of groundwater made it possible to carry out frequent irrigation at low rates, which made it possible to maintain optimal soil moisture; as a result, the nutrients were constantly available in a form accessible to plants. With the use of groundwater for irrigation, additional electricity costs of 14349 MJ/ha appeared. Expanding farmers\u27 access to modern pumping equipment reduces these costs by 25%. An even more dramatic solution is the gradual transition to solar energy use in groundwater extraction, which is the object of further research