Ground-state energy of pionic hydrogen to one loop

We investigate the ground-state energy of the pi- p atom (pionic hydrogen) in the framework of QCD+QED. In particular, we evaluate the strong energy-level shift. We perform the calculation at next-to-leading order in the low-energy expansion in the framework of the relevant effective field theory. The result provides a relation between the strong energy shift and the pion-nucleon S-wave scattering lengths - evaluated in pure QCD - at next-to-leading order in isospin breaking and in the low-energy expansion. We compare our result with available model calculations.Comment: Version accepted for publication in Eur. Phys. J. C; Eq. (B8) corrected, comment after Eq. (B11) changed, additional minor changes in the text; preprint number adde

Comparison of die geometry for cold drawing of multi-rifled steel tubes

Multi-rifled tubes, i.e. tubes with multiple inner grooving are used in heat exchangers and boilers, providing favourable heat transfer conditions due to turbulent flow of cooling medium. Therefore, strict requirements are placed on the geometry of inner rifling. In production of such tubes, cold drawing with free-to-rotate rifled plug is the final drawing operation to achieve required dimensions. A Finite Element Method (FEM) based numerical model of the process was prepared in order to optimize the geometry of the die. The results of numerical simulations for two different die geometries show the difference in material flow and corresponding drawing force. The final dimensions of the tubes after drawing were compared with the customer`s requirements and a good agreement was found

Validation of results of two different reductions for precision seamless cold drawn tubes

This paper deals with the comparison of the seamless pulling process of precision seamless tubes using two different reductions from the viewpoint of geometrical stability using computerized tomography, from the point of view of mechanical properties, from the point of view of the surface temperature in the arrangement of the tribological tube-tool pair. Validation of the pipe drawing process also took place based on the finite element method in the simulation program DEFORM 3D. From the point of view of production rationalization, it is necessary to analyze stress and deformation states at different input dimensions for a particular final dimension for a given drawing method, in this case, a drawing whiteout plug method was used

Chiral condensate thermal evolution at finite baryon chemical potential within Chiral Perturbation Theory

We present a model independent study of the chiral condensate evolution in a hadronic gas, in terms of temperature and baryon chemical potential. The meson-meson interactions are described within Chiral Perturbation Theory and the pion-nucleon interaction by means of Heavy Baryon Chiral Perturbation Theory, both at one loop, and nucleon-nucleon interactions can be safely neglected within our hadronic gas domain of validity. Together with the virial expansion, this provides a systematic expansion at low temperatures and chemical potentials, which includes the physical quark masses. This can serve as a guideline for further studies on the lattice. We also obtain estimates of the critical line of temperature and chemical potential where the chiral condensate melts, which systematically lie somewhat higher than recent lattice calculations but are consistent with several hadronic models. We have also estimated uncertainties due to chiral parameters, heavier hadrons and higher orders through unitarized Chiral Perturbation Theory.Comment: 15 pages, 15 figures, 3 tables, ReVTeX. Version to appear in Phys. Rev. D. References added. More conservative estimate of applicability domain, with new figure. More detailed explanation of final results with two more figures. Results unchange

Anti-angiogenic activity of the flavonoid precursor 4-hydroxychalcone.

Angiogenesis, the growth of new blood vessels, is necessary for cancerous tumors to keep growing and spreading. Suppression of abnormal angiogenesis may provide therapeutic strategies for the treatment of angiogenesis-dependent disorders. In the present study, we describe the in vitro and in vivo anti-angiogenic activities of the flavonoid precursor 4-hydroxychalcone (Q797). This chalcone (22μg/ml) suppressed several steps of angiogenesis, including endothelial cell proliferation, migration and tube formation without showing any signs of cytotoxicity. Moreover, we found a selective effect on activated endothelial cells, in particular with resting endothelial cells and the human epithelial tumor cell lines (HeLa, MCF-7, A549). In addition, Q797 was able to modulate both vascular endothelial growth factor (VEGF)- and basic fibroblast growth factor (FGF)- induced phosphorylation of extracellular signal-regulated kinase (ERK)-1/-2 and Akt kinase. It did not influence the nuclear translocation of p65 subunit of the nuclear factor-κB (NF-κB) when human endothelial cells were stimulated with tumor necrosis factor (TNF)-α. Taken together this indicates that the Q797-mediated inhibition of in vitro angiogenic features of endothelial cells is most likely caused by suppression of growth factor pathways. The potent inhibitory effect of Q797 on bFGF-driven neovascularization was also demonstrated in vivo using the chick chorioallantoic membrane (CAM) assay. In summary, this chalcone could serve as a new leading structure in the discovery of new potent synthetic angiogenesis inhibitors

Meson-baryon scattering lengths in HBχ\chiPT

We calculate the chiral corrections to the s-wave pseudoscalar meson octet-baryon scattering lengths $a_{MB}$ to ${\cal O}(p^3)$ in the SU(3) heavy baryon chiral perturbation theory (HB$\chi$PT). Hopefully the obtained analytical expressions will be helpful in the chiral extrapolation of these scattering lengths in the future lattice simulation.Comment: 14 pages, 1 figure, 7 table

Evaluation of vaccine-induced maternal immunity against classical swine fever

The vaccine-induced maternal immunity against classical swine fever (CSF) was investigated in this study. Eight sows were vaccinated with the Chinese strain of classical swine fever virus (CSFV). The length of time between vaccination and farrowing was 167-217 days. Milk samples from the front, middle and back udder sections and blood samples were taken from the sows on days 3 and 14 after farrowing. Blood samples were obtained from the piglets at the age of 3, 6 and 10 weeks. The antibody level of the milk was examined by ELISA, and that of blood samples by the virus neutralization (VN) test as well. In all 3-week-old piglets and in 80% of the 6-week-old animals the neutralizing antibody level reached the titre of 1:40. In none of the 10-week-old piglets did the titre exceed the value of 1:20, but in about 25% of the piglets it reached 1:20; the half of these piglets came from two litters. In none of the piglets did the antibody level reach the negative threshold in the ELISA test during the study. No significant differences were found between the udder sections in milk antibody level by ELISA

(E)-1-(2,5-Dimethyl-3-thien­yl)-3-(2-hy­droxy­phen­yl)prop-2-en-1-one

In the title compound, C15H14O2S, the dihedral angle between the aromatic rings is 8.46 –(8)°. The central enone group is planar (r.m.s. deviation = 0.0267 Å) and is oriented at a dihedral angle of 1.20 (9)° with respect to the benzene ring and at 8.27 (9)° with respect to the thio­phene group. In the crystal, the mol­ecules are linked into polymeric chains extending along the b axis due to inter­molecular O—H⋯O hydrogen bonding. An S(6) ring motif is formed due to a short intra­molecular C—H⋯O contact. C—H⋯π inter­actions involving a methyl group of the 2,5-dimethyl­thienyl group and the benzene ring are present. π–π inter­actions between the centroids of the benzene and heterocyclic rings [3.7691 (9) Å] also occur

U(3) chiral perturbation theory with infrared regularization

We include the eta-prime in chiral perturbation theory without employing 1/N_c counting rules. The method is illustrated by calculating the masses and decay constants of the Goldstone boson octet (pions, kaons, eta) and the singlet eta-prime up to one-loop order. The effective Lagrangian describing the interactions of the eta-prime with the Goldstone boson octet is presented up to fourth chiral order and the loop integrals are evaluated using infrared regularization, which preserves Lorentz and chiral symmetry.Comment: 29 page