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San Luis Potosi, Mexico

The Autonomous University of San Luis Potosí is a public university in Mexico. It is the largest university in the state of San Luis Potosí. Among other historic milestones, in 1923 UASLP was the first university in Mexico to have autonomy constitutionally granted. Wikipedia.

Quintana M.,Autonomous University of San Luis Potosi | Vazquez E.,University of Castilla - La Mancha | Prato M.,University of Trieste
Accounts of Chemical Research

Graphene is considered a promising material for a range of new applications from flexible electronics to functional nanodevices, such as biosensors or intelligent coatings. Therefore researchers need to develop protocols for the mass production of graphene. One possible method is the exfoliation of graphite to form stable dispersions in organic solvents or even water. In addition, researchers need to find effective ways to control defects and locally induced chemical changes. We expect that traditional organic chemistry can provide solutions to many of these challenges. In this Account, we describe our efforts toward the production of stable dispersions of graphene in a variety of solvents at relatively high concentrations and summarize representative examples of the organic reactions that we have carried out using these stable dispersions.The sonication procedures used to solubilize graphene can often damage these materials. To mitigate these effects, we developed a new methodology that uses mechanochemical activation by ball-milling to exfoliate graphite through interactions with melamine (2,4,6-triamine-1,3,5-triazine) under solid conditions. Alternatively, the addition of reducing agents during sonication leads to larger graphene layers in DMF. Interestingly, the treatment with ferrocene aldehyde, used as a radical trap, induces the formation of multiwalled carbon nanotubes. The resulting graphene sheets, stabilized by the interactions with the solvent, are suitable materials for performing organic reactions.Relatively few organic reactions have been performed in stable dispersions of graphene, but organic functionalization of these materials offers the opportunity to tune their properties. In addition, thermal treatments can remove the appended organic moieties, restoring the intrinsic properties of pristine graphene. We describe a few examples of organic functionalization reactions of graphene, including 1,3-dipolar cycloadditions, amide condensations, nitrene additions, and radical reactions. The design of novel protocols for further organic functionalization should increase our knowledge of the fundamental chemistry of graphene and spur the further development and application of these materials. © 2012 American Chemical Society. Source

Rosales-Mendoza S.,Autonomous University of San Luis Potosi
Expert review of vaccines

Besides serving as a valuable model in biological sciences, Chamydomonas reinhardtii has been used during the last decade in the biotechnology arena to establish models for the low cost production of vaccines. Antigens from various pathogens including Plasmodium falciparum, foot and mouth disease virus, Staphylococcus aureus, classical swine fever virus (CSFV) as well as some auto-antigens, have been produced in C. reinhardtii. Although some of them have been functionally characterized with promising results, this review identifies future directions for the advancement in the exploitation of this robust and safe vaccine production platform. The present analysis reflects that important immunological implications exist for this system and remain unexplored, including the possible adjuvant effects of algae biomolecules, the effect of bioencapsulation on immunogenicity and the possible development of whole-cell vaccines as an approach to trigger cytotoxic immune responses. Recently described molecular strategies that aim to optimize the expression of nuclear-encoded target antigens are also discussed. Source

Fahraeus R.,University Paris Diderot | Olivares-Illana V.,Autonomous University of San Luis Potosi

MDM2 is considered a hub protein due to its capacity to interact with a large number of different partners of which p53 is most well described. MDM2 is an E3 ubiquitin ligase, and many, but not all, of its interactions relate directly to this activity, such as substrates, adaptors or bridges, promoters, inhibitors or complementary factors. Some interactions serve regulatory functions that in response to cellular stresses control the localisation and functions of MDM2 including protein kinases, ribosomal proteins and proteases. Moreover, interactions with nucleotides serve other functions such as mRNA to regulate protein synthesis and DNA to control transcription. To perform such a pleiotropic panorama of different functions, MDM2 is subjected to a multitude of post-translational modifications and is expressed in different isoforms. The large and diverse interactome is made possible due to the plasticity of MDM2 and in this review we have listed the MDM2 interactions until now and we will discuss how this multifaceted protein can interact with such a variety of substrates to provide a key intermediary role in different signalling pathways. Source

Campos-Delgado D.U.,Autonomous University of San Luis Potosi | Espinoza-Trejo D.R.,Autonomous University of San Luis Potosi
IEEE Transactions on Industrial Electronics

In this paper, the detection and isolation of open-switch faults in induction motor (IM) drives are addressed from a model-based perspective. Residuals are synthesized by using nonlinear observers followed from a directional characterization. First, it is observed that the IM model can be written in a recurrent decoupled structure by taking the stator currents and mechanical velocity as outputs. In this way, residuals can be insensitive to load torque and operating conditions, and simultaneous faults can be addressed. A pulsewidth modulation three-phase inverter is studied as power actuator for the IM. Hence, in order to isolate faults related to the six switching devices, a directional residual evaluation in the dq-frame is employed. Hence, three residuals are constructed to isolate the faulty switches. The ideas presented in this paper are validated experimentally in a test bench of 1-hp IM under single and simultaneous faults. © 2011 IEEE. Source

Ivlev B.,Autonomous University of San Luis Potosi
Annals of Physics

Quantum tunneling through a two-dimensional static barrier becomes unusual when a momentum of an electron has a tangent component with respect to a border of the prebarrier region. If the barrier is not homogeneous in the direction perpendicular to tunneling a fraction of the electron state is waves propagating away from the barrier. When the tangent momentum is zero a mutual interference of the waves results in an exponentially small outgoing flux. The finite tangent momentum destroys the interference due to formation of caustics by the waves. As a result, a significant fraction of the prebarrier density is carried away from the barrier providing a not exponentially small penetration even through an almost classical barrier. The total electron energy is well below the barrier. © 2010 Elsevier Inc. Source

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