Partículas de azogue: Movilidad y desplazamientos sígnicos del exilio cubano

Author contacted on 29/01/2014 to see if he could supply an abstract in English and any copyright information. No reply as of 04/04/2014 so withdrawn for now

MicroRNAs sequencing unveils distinct molecular subgroups of plasmablastic lymphoma

Plasmablastic lymphoma (PBL) is an aggressive lymphoma, often arising in the context of immunodeficiency and associated with Epstein-Barr virus (EBV) infection. The most frequently detected genetic alteration is the deregulation of MYC gene through the translocation - t(8;14)(q24;q32). The diagnosis of PBL is often challenging because it has an overlap in morphology, immunophenotype, cytogenetics and virus association with other lymphomas and plasma cell neoplasms; further, its molecular basis remains elusive. In the present study we aimed to better define the possible contribution of EBV infection as well as miRNA deregulation in PBL pathogenesis. We studied 23 cases of PBL, 19 Burkitt lymphomas (BL), and 17 extra-medullary plasmacytoma (EMPC). We used qPCR and immunohistochemistry to assess EBV latency patterns, while micro-RNA (miRNA) profiling was performed by next generation sequencing (Illumina) and validated by qPCR. Our analysis revealed a non-canonical EBV latency program with the partial expression of some proteins characterizing latency II and the activation of an abortive lytic cycle. Moreover, we identified miRNA signatures discriminating PBL from BL and EMPC. Interestingly, based on the miRNA profile, PBL appeared constituted by two discrete subgroups more similar to either BL or EMPC, respectively. This pattern was confirmed in an independent set of cases studied by qPCR and corresponded to different clinico-pathological features in the two groups, including HIV infection, MYC rearrangement and disease localization. In conclusion, we uncovered for the first time 1) an atypical EBV latency program in PBL; 2) a miRNA signature distinguishing PBL from the closest malignant counterparts; 3) the molecular basis of PBL heterogeneity

Water Dynamics at the Solid-Liquid Interface to Unveil the Textural Features of Synthetic Nanosponges

A Fast-Field-Cycling NMR investigation was carried out on a set of polyurethane cyclodextrin nanosponges, in order to gain information on their textural properties, which have been proven to be quite difficult to assess by means of ordinary porosimetric techniques. Experiments were performed on both dry and wet samples, in order to evaluate the behavior of the "non-exchangeable" C-bound 1H nuclei, as well as the one of the mobile protons belonging to the skeletal hydroxyl groups and the water molecules. The results acquired for the wet samples accounted for the molecular mobility of water molecules within the channels of the nanosponge network, leading back to the possible pore size distribution. Ow-ing to the intrinsic difficulties involved in a quantitative assessment of the textural properties, in the present study we alternatively propose an extension to nanosponges of the concept of "connectivity", which has been already employed to discuss the properties of soils

Easy plasma nano-texturing of PTFE surface: From pyramid to unusual spherules-on-pyramid features

Oxygen plasma etching of polytetrafluoroethylene has been investigated as a way to sculpture nano-features on its surface and producing a super-hydrophobic material in one step. It has been found that, depending on the experimental conditions, the shape of the structures engraved in the polymer surface passes from pyramidal to unique pyramids with well-defined spherules on the top. The latter are obtained without any mask/lithographic option. In a previous paper the water repellent character of such etched polytetrafluoroethylene surface has been well documented and explained by some of the authors. In this paper, instead, some insights in the formation mechanism of such unusual morphology are provided. Chemical and morphological characterization indicate in the iron surface contamination the clue for the formation of such complex agglomerates

A new heuristic algorithm for the analysis of NMRD dispersion curves

Regression analysis of the NMRD dispersion curves obtained by the FFC-NMR relaxometric technique involves several conceptual and practical issues, which must be carefully addressed in order to gain reliable information on the system studied. Indeed, particular caution is needed when the FFC technique is applied to the investigation of complex systems such as polymeric matrixes, porous materials, food samples, and so on. In these cases, and in general whenever a rigorous approach based on a suitable physical modelization of the system is not available, data analysis must be performed by means of a “model–free” approach. Moving forward from previous literature, in the present communication we propose a new analysis method relying on the elaboration of the inverse integral transform of the NMRD curve, with the well-known BPP function as the kernel. Our approach results in a true heuristic method, able to unambiguously individuate the dynamic domains present in the system, and to avoid the possible introduction of any element of discretion. Moreover, the analysis is supplemented by a Monte-Carlo approach, in order to calculate the indetermination of the regression parameters and to individuate possible artifacts. Analysis of some datasets relevant to real samples, suggests the possibility that the results obtained with the heuristic method may be actually led back to some distinct physical/chemical features of the systems

APPLICATION OF FFC-NMR TECHNIQUES FOR THE STUDY OF THE FEATURES OF NANOSPONGES

Fast-Field-Cycling (FFC) NMR relaxometry is a versatile and powerful tool for studying the microscopic dynamics of molecular systems, provided that a suitable analysis of the longitudinal relaxation kinetics and the relevant NMRD (i.e. longitudinal relaxation rate R1 vs. Larmor frequency νL) dispersion curves is performed. In particular, FFC-NMR can afford valuable information on the texture properties (average pore size, specific surface and specific pore volume) of porous materials, once they have been saturated with water. Thus, it appears a technique of choice for assessing the otherwise elusive texture properties of nanosponges (NSs). These hyper-crosslinked polymers, obtained by reticulating cyclodextrins with suitable linker units, constitute an emerging class of functional materials due to their easy synthesis and chemical modification, and to their tunable absorption and controlled release abilities as well. NSs are supposed to possess a thick network of nanochannels in their highly disordered structure. However, their textural features are quite difficult to estimate partly because of their fair swellability, and classical evaluation methodologies such as N2 absorption isotherms analyzed by BET/BJH methods, or dye absorption isotherms, have afforded questionable results. Here we present some results from FFC-NMR investigations performed on a set of suitably selected NSs, aimed at providing a viable method to evaluate their texture properties, as well as the functional mobility of a water medium within their pore network. In particular, inspired by soil science, we tried to extend to NSs the concept of “connectivity”,[1] by defining a “Pore Connectivity Index” (PCI)[2] based on T1 realxation times distribution functions, which may constitute a valuable alternative to quantify the permeability of NSs. Moreover, by assessing the mobility of water molecules in terms of the relevant correlation times τc, estimated by means of a new heuristic analysis method of NMRD curves,[3] we attempted to rationalize their controlled release abilities

MYC protein expression scoring and its impact on the prognosis of aggressive B-cell lymphoma patients

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