Three body systems with strangeness and exotic systems

We report on four $\Sigma$'s and three $\Lambda$'s, in the 1500 - 1800 MeV region, as two meson - one baryon S-wave $(1/2)^+$ resonances found by solving the Faddeev equations in the coupled channel approach, which can be associated to the existing $S$ = -1, $J^P= 1/2^+$ low lying baryon resonances. On the other hand we also report on a new, hidden strangeness $N^*$ state, mostly made of $K \bar{K} N$, with mass around 1920 MeV, which we think could be responsible for the peak seen in the $\gamma p \to K^+ \Lambda$ around this energy. Finally we address a very novel topic in which we show how few body systems of several $\rho$ mesons can be produced, with their spins aligned up to J=6, and how these states found theoretically can be associated to several known mesons with spins J=2,3,4,5,6.Comment: Talk at the 21st European Conference on Few Body Problems in Physics, Salamanca, Sep. 201

Superficial Surface Treatment using Atmospheric Plasma on Recycled Nylon 6,6

Polymers currently represent materials that are cost-effective, while its recycled nature is significant in terms of environmental protection. However, the surface properties of polymers often do not meet the demands of wettability, adhesion, and friction, among others. Atmospheric plasma treatment on the surface of polymers improves its physical-chemistry properties. In this work, a recycled nylon coating was prepared by the spin coating technique and characterized by Fourier transform infrared spectroscopy and X-ray diffraction. This coating was treated by atmospheric plasma, and Raman spectroscopy was performed to analyze the signals related to different functional groups present in the coating surface after plasma treatment. The action of plasma on the surface morphology was observed by scanning electron microscopy. The contact angle results showed an improvement in surface wettability

Chiral magnetization textures stabilized by the Dzyaloshinskii-Moriya interaction during spin-orbit torque switching

We study the effect of the Dzyaloshinskii-Moriya interaction (DMI) on current-induced magnetic switching of a perpendicularly magnetized heavy-metal/ferromagnet/oxide trilayer both experimentally and through micromagnetic simulations. We report the generation of stable helical magnetization stripes for a sufficiently large DMI strength in the switching region, giving rise to intermediate states in the magnetization confirming the essential role of the DMI on switching processes. We compare the simulation and experimental results to a macrospin model, showing the need for a micromagnetic approach. The influence of the temperature on the switching is also discussed.Comment: Includes corrected acknowledgements and clarification of simulation parameter

Gnathostomosis, an emerging foodborne zoonotic disease in Acapulco, Mexico.

Between 1993 and 1997, 98 gnathostomosis cases were clinically identified in Acapulco, Mexico. Intermittent cutaneous migratory swellings were the commonest manifestation. Larvae were identified in 26 cases, while in 72, final diagnosis was made on the basis of epidemiologic data, food habits, and positive enzyme-linked immunosorbent assay and Western blot results

Dynamically generated resonances

In this talk I report on recent work related to the dynamical generation of baryonic resonances, some made up from pseudoscalar meson-baryon, others from vector meson-baryon and a third type from two meson-one baryon systems. We can establish a correspondence with known baryonic resonances, reinforcing conclusions previously drawn and bringing new light on the nature of some baryonic resonances of higher mass.Comment: Talk given at the Workshop on physics of the excited nucleon-NSTAR 2009, Beijing, april 200

Magnetic moments of the low-lying JP= 1/2−J^P=\,1/2^-, 3/2−3/2^- Λ\Lambda resonances within the framework of the chiral quark model

The magnetic moments of the low-lying spin-parity $J^P=$ $1/2^-$, $3/2^-$ $\Lambda$ resonances, like, for example, $\Lambda(1405)$ $1/2^-$, $\Lambda(1520)$ $3/2^-$, as well as their transition magnetic moments, are calculated using the chiral quark model. The results found are compared with those obtained from the nonrelativistic quark model and those of unitary chiral theories, where some of these states are generated through the dynamics of two hadron coupled channels and their unitarization

Multi-step biocatalytic strategies for chiral amino alcohol synthesis

Chiral amino alcohols are structural motifs present in sphingolipids, antibiotics, and antiviral glycosidase inhibitors. Their chemical synthesis presents several challenges in establishing at least two chiral centres. Here a de novo metabolic pathway using a transketolase enzyme coupled with a transaminase enzyme has been assembled. To synthesise this motif one of the strategies to obtain high conversions from the transaminase/transketolase cascade is the use of hydroxypyruvate (HPA) as a two-carbon donor for the transketolase reaction; although commercially available it is relatively expensive limiting application of the pathway on an industrial scale. Alternately, HPA can be synthesised but this introduces a further synthetic step. In this study two different biocatalytic strategies were developed for the synthesis of (2S,3R)-2-amino-1,3,4-butanetriol (ABT) without adding HPA into the reaction. Firstly, a sequential cascade of three enzymatic steps (two transaminases and one transketolase) for the synthesis of ABT from serine, pyruvate and glycolaldehyde as substrates. Secondly, a two-step recycling cascade where serine is used as donor to aminate erythrulose (catalysed by a transketolase) for the simultaneous synthesis of ABT and HPA. In order to test the novel pathways, three new transaminases are described, two ω-transaminases able to accept a broad range of amine acceptors with serine as amine donor; and an α-transaminase, which showed high affinity towards serine (KM: 18mM) using pyruvate as amine acceptor. After implementation of the above enzymes in the biocatalytic pathways proposed in this paper, the two-step recycling pathway was found to be the most promising for its integration with E. coli metabolism. It was more efficient (10-fold higher conversion), more sustainable and cost-effective (use of low cost natural substrates and only two enzymes), and the reaction could be performed in a one-pot system

Radiative open charm decay of the Y(3940), Z(3930), X(4160) resonances

We determine the radiative decay amplitudes for decay into $D^*$ and $\bar{D} \gamma$, or $D^*_s$ and $\bar{D}_s \gamma$ of some of the charmonium like states classified as X,Y,Z resonances, plus some other hidden charm states which are dynamically generated from the interaction of vector mesons with charm. The mass distributions as a function of the $\bar{D} \gamma$ or $\bar{D}_s \gamma$ invariant mass show a peculiar behavior as a consequence of the $D^* \bar{D}^*$ nature of these states. The experimental search of these magnitudes can shed light on the nature of these states.Comment: 18 pages, 9 figure