Biomedical subjects
Publications and source records attributed to Daniel Alonso.
Ten new pentasaccharide glycosides, arboresins 1-6 (1-6) and murucins 6-9 (8-11), along with five known glycolipids, were isolated from the roots of Ipomoea arborescens, and their structures were elucidated by spectroscopic and chemical methods. Compounds 1-6 and 8-11 were evaluated for cytotoxicity against a small panel of cancer cell lines.
We derive the dynamical equation of the reduced propagator, an object that evolves state vectors of the system conditioned to the dynamics of its environment, which is not necessarily in the vacuum state at the initial time. Such a reduced propagator is essential to obtain multiple-time correlation functions (MTCFs). We also study the evolution of MTCFs within the weak-coupling limit and show that the quantum regression theorem is, in general, not satisfied. We illustrate the theory in two different cases: first, solving an exact model, and, second, presenting the results of the numerical integration for a system coupled with a thermal environment through a nondiagonal interaction.
Stochastic Schrodinger equations are used to describe the dynamics of a quantum open system in contact with a large environment, as an alternative to the commonly used master equations. We present a study of the two main types of non-Markovian stochastic Schrodinger equations, linear and nonlinear ones. We compare them both analytically and numerically, the latter for the case of a spin-boson model. We show in this paper that two linear stochastic Schrodinger equations, derived from different perspectives by Diosi, Gisin, and Strunz [Phys. Rev. A 58, 1699 (1998)], and Gaspard and Nagaoka [J. Chem. Phys. 13, 5676 (1999)], respectively, are equivalent in the relevant order of perturbation theory. Nonlinear stochastic Schrodinger equations are in principle more efficient than linear ones, as they determine solutions with a higher weight in the ensemble average which recovers the reduced density matrix of the quantum open system. However, it will be shown in this paper that for the case of a spin-boson system and weak coupling, this improvement does only occur in the case of a bath at high temperature. For low temperatures, the sampling of realizations of the nonlinear equation is practically equivalent to the sampling of the linear ones. We study further this result by analyzing, for both temperature regimes, the driving noise of the linear equations in comparison to that of the nonlinear equations.
Five pentasaccharide glycosides, murucins 1-5 (1-5), were isolated from the roots of the arboreal species Ipomoea murucoides, and their structures were elucidated by spectroscopic and chemical methods. Compounds 1-5 were evaluated for cytotoxicity against a small panel of cancer cell lines.
The epidermal growth factor receptor (EGFR) is highly expressed in many types of epithelial tumors. EGFR overexpression has been associated with an advanced stage of the disease, with resistance to standard therapies, and, for certain tumors, with poor patient prognosis. As a result, EGFR has been considered a meaningful target in anti-tumor strategies. Active and passive immunotherapies blocking EGFR and its ligands have been explored. But for successful pre-clinical evaluation of these approaches, well-established murine tumor models are not available and highly desirable. We described, for the first time, the generation and characterization of an anti-murine EGFR extracellular domain monoclonal antibody (7A7 MAb) (IgG1). 7A7 was generated by immunization of Balb/c mice with the recombinant extracellular domain of murine EGFR (rECD-mEGFR). 7A7 recognized an epitope present in the amino acidic core of the antigen and is cross-reactive with the human EGFR. Interestingly, this MAb was able to specifically bind EGFR at the cell surface, allowing the assessment of its differential expression in a panel of murine cells. Noteworthy, in a preliminary immunohistochemical study with 7A7 MAb, recognition of Balb/c mice skin sections and EGFR-positive tumors were observed. We concluded that 7A7 MAb is a valuable tool for EGFR-based therapeutic pre-clinical studies.
A detail study of the diffusive and heat conduction properties of a family of nonchaotic billiards is presented. For dynamical systems with dynamical instability the relation between transport properties and characteristic quantities of the chaotic dynamics naturally emerge. On the contrary, in dynamical systems without chaos (in the sense of exponential separation of nearby trajectories) much less is known. From numerical simulations we compute several quantities related to diffusion, such as the mean square displacement, the behavior of the hydrodynamic modes for long wavelengths, through the properties of the incoherent intermediate scattering function and the velocity autocorrelation function, in connection with the Green-Kubo formula. The analysis of all these quantities indicates that some systems among the family studied have normal diffusion and others anomalous diffusion. The spectral measure associated with the velocity autocorrelation function is also studied. The same analysis reveals that for all the systems treated there is not a well defined super Burnett coefficient. The heat conduction is also explored and found that, naturally, it is valid for the systems that behave diffusively.