Primary amebic meningoencephalitis (PAM) caused by the free-living ameba Naegleria fowleri is a rare but rapidly fatal disease of the central nervous system (CNS) affecting predominantly young, previously healthy persons. No effective chemotherapeutic prophylaxis or treatment has been identified. Recently, three transplant-associated clusters of encephalitis caused by another free-living ameba, Balamuthia mandrillaris, have occurred, prompting questions regarding the suitability of extra-CNS solid organ transplantation from donors with PAM. During 1995–2012, 21 transplant recipients of solid organs donated by five patients with fatal cases of PAM were reported in the United States. None of the recipients developed PAM and several recipients tested negative for N. fowleri by serology. However, historical PAM case reports and animal experiments with N. fowleri, combined with new post-mortem findings from four PAM patients, suggest that extra-CNS dissemination of N. fowleri can occur and might pose a risk for disease transmission via transplantation. The risks of transplantation with an organ possibly harboring N. fowleri should be carefully weighed for each individual recipient against the potentially greater risk of delaying transplantation while waiting for another suitable organ. In this article we present a case series and review existing data to inform such risk assessments.

The dependence between neutron-to-proton yield ratio (R np ) and neutron skin thickness (δ np ) in neutronrich projectile induced reactions is investigated within the framework of the Isospin-Dependent Quantum Molecular Dynamics (IQMD) model. The density distribution of the Droplet model is embedded in the initialization of the neutron and proton densities in the present IQMD model. By adjusting the diffuseness parameter of neutron density in the Droplet model for the projectile, the relationship between the neutron skin thickness and the corresponding R np in the collisions is obtained. The results show strong linear correlation between R np and δ np for neutron-rich Ca and Ni isotopes. It is suggested that R np may be used as an experimental observable to extract δ np for neutron-rich nuclei, which is very significant to the study of the nuclear structure of exotic nuclei and the equation of state (EOS) of asymmetric nuclear matter. Key words: isospin, neutron-proton ratio, neutron skinNuclear radius is one of the basic quantities of a nucleus. The proton root-mean-square (RMS) radius can be determined to very high accuracy via the charge radius measured by electromagnetic interactions, typically with an error of 0.02 fm or better for many nuclei [1]. In contrast, it is much more difficult to accurately determine the neutron density distribution of a nucleus experimentally [2]. Thus, the accuracy of experimental neutron radius is much lower than that of the proton radius. However, the information of neutron density is very important to the study of nuclear structure for neutron-rich nuclei, atomic parity non-conservation, iso-vector interactions, and neutron-rich matter in astrophysics etc. It is remarkable that a single measurement has so many applications in the research fields of atomic, nuclear and astrophysics [3,4]. A nucleus with neutron number (N ) being larger than proton number (Z) are expected to have a neutron skin (defined as the difference between the neutron and proton RMS radii: δ np ≡ r 2 n 1/2 − r 2 p 1/2 ). The neutron skin thickness δ np depends on the balance between various aspects of the nuclear force. The actual proton and neutron density distributions are determined by the balance between the isospin asymmetry and Coulomb force. δ np is found to be related with a constraint on the equation of state (EOS) of asymmetric nuclear matter. Strong linear correlation between δ np and L (the slope of symmetry energy coefficient C sym ), the ratio L/J (J is the symmetry energy coefficient at the saturation density ρ 0 ), J − a sym (a sym is the symmetry energy coefficient of finite nuclei) are demonstrated [5]. This constraint is important for extrapolation of the EOS to high density and hence useful for studying properties of neutron star [5,6,7,8,9,10,11,12]. Neutron skin thickness can yield a lot of information on the derivation of volume and surface symmetry energy, as well

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[reaction: see text] A novel crystallization-induced chiral inversion of (S)-2-bromo-3-phenylpropanoic acid to its (R)-enantiomer with excellent enantiomeric excess (96-99%) is achieved. Optically pure (S)-2-acetylthio-3-phenylpropanoic acid can be prepared in good yield from inexpensive and commercially available l-phenylalanine via diazotization/bromination, chiral inversion, and thioacetate substitution reactions.