Parity nonconservation in deuteron photoreactions

We calculate the asymmetries in parity nonconserving deuteron photodisintegration due to circularly polarized photons gamma+d to n+p with the photon laboratory energy ranging from the threshold up to 10 MeV and the radiative capture of thermal polarized neutrons by protons n+p to gamma+d. We use the leading order electromagnetic Hamiltonian neglecting the smaller nuclear exchange currents. Comparative calculations are done by using the Reid93 and Argonne v18 potentials for the strong interaction and the DDH and FCDH "best" values for the weak couplings in a weak one-meson exchange potential. A weak NDelta transition potential is used to incorporate also the Delta(1232)-isobar excitation in the coupled-channels formalism.Comment: 14 pages, 13 figures (18 eps files), LaTeX2

A novel repair method for the treatment of acute Achilles tendon rupture with minimally invasive approach using button implant: A biomechanical study

PubMedID: 24095235Background: Minimally invasive Q3 repair has been proposed for acute Achilles tendon rupture with low rate of complications. However there are still controversies about optimal technique. In this study we aimed to describe Endobutton-assisted modified Bunnell configuration as a new Achilles tendon repair technique and evaluate its biomechanical properties comparing with native tendon and Krackow technique. Methods: 27 ovine Achilles tendons were obtained and randomly placed into 3 groups with 9 specimens ineach. The Achilles tendons were repaired with Endobutton-assisted modified Bunnell technique in group 1, Krackow suture technique in group 2 and group 3 was defined as the control group including native tendons. Unidirectional tensile loading to failure was performed at 25. mm/min. Biomechanicalproperties such as peak force to failure (N), stress at peak (MPa), elongation at failure, and Young'smodulus (GPa) was measured for each group. All groups were compared with each other using one-wayANOVA followed by the Tukey HSD multiple comparison test (a. = 0.05). Results: The average peak force (N) to failure of group 1 and group 2 and control group was 415.6. ±. 57.6, 268.1. ±. 65.2 and 704.5. ±. 85.8, respectively. There was no statistically significant difference between native tendon and group 1 for the amount elongation at failure (p. >. 0.05). Conclusions: Regarding the results, we concluded that Endobutton-assisted modified Bunnell technique provides stronger fixation than conventional techniques. It may allow early range of motion and can be easily applied in minimally invasive and percutaneous methods particularly for cases with poor quality tendon at the distal part of rupture. Level of evidence: Level II, Biomechanical research study. © 2013 European Foot and Ankle Society

Identification of 6 '-beta-fluoro-homoaristeromycin as a potent inhibitor of chikungunya virus replication

We have reported on aristeromycin (1) and 6'-fluorinated-aristeromycin analogues (2), which are active against RNA viruses such as Middle East respiratory syndrome coronavirus (MERS-CoV), severe acute respiratory syndrome coronavirus (SARS-CoV), Zika virus (ZIKV), and Chikungunya virus (CHIKV). However, these exhibit substantial cytotoxicity. As this cytotoxicity may be attributed to 5'-phosphorylation, we designed and synthesized one-carbon homologated 6'-fluorinated-aristeromycin analogues. This modification prevents 5'-phosphorlyation by cellular kinases, whereas the inhibitory activity towards S-adenosyk-homocysteine (SAH) hydrolase will be retained. The enantiomerically pure 6'-fluorinated-5'-homoaristeromycin analogues 3a-e were synthesized via the electrophilic fluorination of the silyl enol ether with Selectfluor, using a base-build up approach as the key steps. All synthesized compounds exhibited potent inhibitory activity towards SAH hydrolase, among which 6'-beta-fluoroadenosine analogue 3a was the most potent (IC50 = 0.36 mu M). Among the compounds tested, 6'-beta-fluoro-homoaristeromycin 3a showed potent antiviral activity (EC50 = 0.12 mu M) against the CHIKV, without noticeable cytotoxicity up to 250 mu M. Only 3a displayed anti-CHIKV activity, whereas both3a and 3b inhibited SAH hydrolase with similar IC50 values (0.36 and 0.37 mu M, respectively), which suggested that 3a's antiviral activity did not merely depend on the inhibition of SAH hydrolase. This is further supported by the fact that the antiviral effect was specific for CHIKV and some other alphaviruses and none of the homologated analogues inhibited other RNA viruses, such as SARS-CoV, MERS-CoV, and ZIKV. The potent inhibition and high selectivity index make 6'-beta-fluoro-homoaristeromycin (3a) a promising new template for the development of antivirals against CHIKV, a serious re-emerging pathogen that has infected millions of people over the past 15 years. (C) 2019 Elsevier Masson SAS. All rights reserved.Molecular basis of virus replication, viral pathogenesis and antiviral strategie