1,297 research outputs found

    could the uterine junctional zone be used to identify early stage endometriosis in women

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    Although the correlation between endometriosis, junctional zone (JZ) hyperplasia and adenomyosis is still debated, the correlation among JZ and different etiological and clinical aspects is, today, well recognized. Starting from that, clinicians must consider in their own practice all the potential modifications of the JZ because the described could be correlated with reproductive or obstetrics disorders [1]. The accurate and analytical evaluation, case by case, of the JZ is one of the most crucial points in the flowchart of infertile patients and also endometriotic patients. An accurate evaluation of JZ and its potential modifications can provide important information for patients with endometriosis and/or infertility or chronic pelvic pain. We know that adenomyosis is a common gynecologic disease characterized by the migration of endometrial glands and stroma from the basal layer of endometrium into the myometrium, and could be associated with smooth muscle hyperplasia. The first author that mentioned adenomyosis and its histopathological features was Rokitansky in 1860 describing the invasion of stroma and endometrial glands inside the myometrium with different levels of invasion up to the serosa [2]. A common pathogenesis for adenomyosis and endometriosis has been hypothesized, and it is argued that endometrial stroma being in direct contact with the underlying myometrium allows communication and interaction, thus facilitating endometrial invagination or invasion of a structurally weakened myometrium during periods of regeneration, healing and re-epithelization. Dislocation of basal endometrium may also result in endometriosis through retrograde menstruation [3]. Pelvic endometriosis and uterine adenomyosis are variants of the same disease, which involves the dislocation of basal endometrium and results from a dysfunction and disease primarily at the level of the JZ [4]. Pelvic endometriosis, especially in its severe stages, is also strongly associated with JZ thickening [5–8]. Therefore, the evaluation of JZ and its alterations by non invasive imaging are very important, especially in patients with endometriosis. Adenomyosis is also defined as the chronic disruption of the boundary between the basal layer of the endometrium and the myometrium, known as the JZ, with the hallmark pathologic finding of endometrial glands and stroma within the myometrium [9]. Both parts of the JZ (endometrium and subendometrial myometrium) have a common embryological origin from the paramesonephric ducts and show cyclical changes during the menstrual cycle, whereas the outer myometrium is of nonparamesonephric mesenchymal origin [10]. The etiology of adenomyosis is not known, but there are recent interesting theories that consider adenomyosis as an expression of pathological endomyometrial JZ, trying to explain, in this Could the uterine junctional zone be used to identify early-stage endometriosis in women

    Ab initio study of the role of defects on the magnetic response and the structural, electronic and hyperfine properties of ZnFe2O4

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    In this work the effects of defects (oxygen vacancies, cationic inversion) on the structural, electronic and the magnetic response of the spinel ZnFe2O4 (ZFO) are studied by using a density functional theory (DFT) based ab initio method (the Full-Potential Linearized Augmented Plane Waves plus Local Orbitals, LAPW+lo) on the framework of the Generalized Gradient Approximation plus U (GGA+U) level. The changes induced by the defects in the hyperfine interactions at the Fe sites of the structure are also presented. In order to discuss the magnetic ordering and the electronic structure of the system we considered different spin arrangements. We found that, similar to the normal and pristine case, reduced and partially inverted ZFO presents an energy landscape characterized by a large number of metastable states. Our calculations successfully describe the hyperfine properties (isomer shift, magnetic hyperfine field and quadrupole splitting) at the Fe sites that are seen by Mössbauer Spectrocopy (MS) at 4 and 300 K, enabling us to characterize the local structure around Fe atoms. Our LAPW+lo predictions also demonstrate the relevance of both oxygen vacancies and antisites (cationic inversion) in the formation of local ferromagnetic coupling between Fe ions, giving rise to a ferrimagnetic ordering in an otherwise antiferromagnetic compound. This results support conclusions based in experimental results obtained in x-ray magnetic circular dichroism and magnetization measurements performed on zinc ferrites with different cation distributions and oxygen vacancy concentrations reported in the literature.Fil: Melo Quintero, Jhon Jaither. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Salcedo Rodriguez, Karen Lizeth. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: RodrÍguez Torres, Claudia Elena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de FĂ­sica; ArgentinaFil: Errico, Leonardo Antonio. Universidad Nacional del Noroeste de la Provincia de Buenos Aires. Departamento de Ciencias BĂĄsicas y Experimentales; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; Argentin

    Study of the relation between oxygen vacancies and ferromagnetism in Fe-doped TiO2 nano-powders

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    In this work, we present an experimental and theoretical study of structural and magnetic properties of Fe doped rutile TiO2 nanopowders. We show that Fe-doping induces the formation of oxygen vacancies in the first-sphere coordination of iron ions, which are in +2 and +3 oxidation states. We found that Fe ions form dimers that share one oxygen vacancy in the case of Fe3+ and two oxygen vacancies in the case of Fe2+. The saturation magnetization is almost independent of iron concentration and slightly increases with the relative fraction of Fe2+. Ab initio calculations show that two Fe ions sharing an oxygen vacancy are coupled ferromagnetically, forming a bound magnetic polaron (BMP), but two neighbor BMPs are aligned antiparallel to each other. Extra electron doping plays a fundamental role mediating the magnetic coupling between the ferromagnetic entities: carriers, possibly concentrated at grain boundaries, mediate between the BMP to produce ferromagnetic alignment.Fil: Mudarra Navarro, Azucena Marisol. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: RodrÍguez Torres, Claudia Elena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Bilovol, Vitaliy. Universidad de Buenos Aires. Facultad de IngenierĂ­a. Departamento de FĂ­sica. Laboratorio de SĂłlidos Amorfos; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; ArgentinaFil: Cabrera, Alejandra Fabiana. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Errico, Leonardo Antonio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; Argentina. Universidad Nacional del Noroeste de la Provincia de Buenos Aires; ArgentinaFil: Weissmann, Mariana Dorotea. ComisiĂłn Nacional de EnergĂ­a AtĂłmica; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas; Argentin

    High-density ZnO nanowires for cellular biointerfaces: a new role as myogenic differentiation switch

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    The design of artificial platforms for expanding undifferentiated stem cells is of tremendous importance for regenerative medicine [1]. We have recently demonstrated that a ZnO nanowires (NWs) decorated glass support permits to obtain a differentiation switch during proliferation for mesoangioblasts (MABs)– i.e. multipotent progenitor cells which are remarkable candidates for the therapy of muscle diseases [2]. We have optimized the ZnO NWs synthesis on glass surfaces by numerical simulations and experimental systematic investigations, considering zinc speciation and supersaturation [3]. In particular, we demonstrated by numerical simulations that the ligand ethylenediamine, at the isoelectric point of the ZnO NWs tips, can effectively control – at 1:1 stoichiometric ratio with zinc – both speciation and supersaturation of zinc in the nutrient solution. In this regard, we employed ethanolamine (a safer precursor) for in-situ producing ethylenediamine by means of a zinc-catalysed amination reaction of ethanolamine by ammonia. The obtained highquality ZnONWs-cells biointerface allows cells to maintain viability and a spherical viable undifferentiated state during the 8 days observation time. Simulations of the interface by theoretical models [4] and our experimental investigations by SEM and confocal microscopy demonstrate that NWs do not induce any damage on the cellular membrane, whilst blocking their differentiation. More specifically, the myosin heavy chain, typically expressed in differentiated myogenic progenitors, is completely absent. Interestingly, the differentiation capabilities are completely restored upon cell removal from the NW-functionalized substrate and regrowing onto a standard culture glass dish. These results open the way towards unprecedented applications of ZnO NWs for cell-based therapy and tissue engineering [5]. References [1] G. Cossu, P. Bianco, Curr. Opin. Genet. Dev. 2003, 13, 537-542. [2] V. Errico, G. Arrabito, E. Fornetti, C. Fuoco, S. Testa, G. Saggio, S. Rufini, S. M. Cannata, A. Desideri, C. Falconi, C. Gargioli, ACS Appl. Mater. Interfaces, 2018, 10, 14097- 14107. [3] G. Arrabito, V. Errico, Z. Zhang, W. Han, C. Falconi, Nano Energy, 2018, 46, 54-62. [4] N. Buch-MĂ„nson, S. Bonde, J. Bolinsson, T. Berthing, J. NygĂ„rd, K.L. Martinez, Adv. Funct. Mater. 2015, 25, 3246-3255. [5] Y. Su, I. Cockerill, Y. Wang, Y.-X. Qin, L. Chang, Y. Zheng, and D. Zhu, Trends in Biotechnology, 2019, 37, 428-441

    Quantitative Measurement of the Affinity of Toxic and Nontoxic Misfolded Protein Oligomers for Lipid Bilayers and of its Modulation by Lipid Composition and Trodusquemine.

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    Many neurodegenerative diseases are associated with the self-assembly of peptides and proteins into fibrillar aggregates. Soluble misfolded oligomers formed during the aggregation process, or released by mature fibrils, play a relevant role in neurodegenerative processes through their interactions with neuronal membranes. However, the determinants of the cytotoxicity of these oligomers are still unclear. Here we used liposomes and toxic and nontoxic oligomers formed by the same protein to measure quantitatively the affinity of the two oligomeric species for lipid membranes. To this aim, we quantified the perturbation to the lipid membranes caused by the two oligomers by using the fluorescence quenching of two probes embedded in the polar and apolar regions of the lipid membranes and a well-defined protein-oligomer binding assay using fluorescently labeled oligomers to determine the Stern-Volmer and dissociation constants, respectively. With both approaches, we found that the toxic oligomers have a membrane affinity 20-25 times higher than that of nontoxic oligomers. Circular dichroism, intrinsic fluorescence, and FRET indicated that neither oligomer type changes its structure upon membrane interaction. Using liposomes enriched with trodusquemine, a potential small molecule drug known to penetrate lipid membranes and make them refractory to toxic oligomers, we found that the membrane affinity of the oligomers was remarkably lower. At protective concentrations of the small molecule, the binding of the oligomers to the lipid membranes was fully prevented. Furthermore, the affinity of the toxic oligomers for the lipid membranes was found to increase and slightly decrease with GM1 ganglioside and cholesterol content, respectively, indicating that physicochemical properties of lipid membranes modulate their affinity for misfolded oligomeric species

    On the deviation from a Curie–Weiss behavior of the ZnFe2O4 susceptibility: A combined ab-initio and Monte-Carlo approach

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    We present a numerical study of the magnetic properties of ZnFe2O4 using Monte-Carlo simulations performed considering a Heisenberg model with antiferromagnetic couplings determined by Density Functional Theory. Our calculations predict that the magnetic susceptibility has a cusp-like peak centered at 13 K, and follows a Curie–Weiss behavior above this temperature with a high and negative Curie–Weiss temperature (ΘCW=−170 K). These results agree with the experimental data once extrinsic contributions that give rise to the deviation from a Curie–Weiss law are discounted. Additionally, we discuss the spin configuration of ZnFe2O4 below its ordering temperature, where the system presents a high degeneracy.Fil: Melo Quintero, Jhon Jaither. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Salcedo Rodriguez, Karen Lizeth. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: GĂłmez AlbarracĂ­n, Flavia Alejandra. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos; ArgentinaFil: Rosales, HĂ©ctor Diego. Universidad Nacional de La Plata. Facultad de IngenierĂ­a. Departamento de Ciencias BĂĄsicas; Argentina. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica de LĂ­quidos y Sistemas BiolĂłgicos; ArgentinaFil: Mendoza ZĂ©lis, Pedro. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Stewart, Silvana Jacqueline. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: Errico, Leonardo Antonio. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; ArgentinaFil: RodrÍguez Torres, Claudia Elena. Consejo Nacional de Investigaciones CientĂ­ficas y TĂ©cnicas. Centro CientĂ­fico TecnolĂłgico Conicet - La Plata. Instituto de FĂ­sica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de FĂ­sica La Plata; Argentin

    Magnetic and structural study of Cu-doped TiO₂ thin films

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    Transparent pure and Cu-doped (2.5, 5 and 10 at.%) anatase TiO₂ thin films were grown by pulsed laser deposition technique on LaAlO₃ substrates. The samples were structurally characterized by X-ray absorption spectroscopy and X-ray diffraction. The magnetic properties were measured using a SQUID. All films have a FM-like behaviour. In the case of the Cu-doped samples, the magnetic cycles are almost independent of the Cu concentration. Cu atoms are forming CuO and/or substituting Ti in TiO₂. The thermal treatment in air promotes the CuO segregation. Since CuO is antiferromagnetic, the magnetic signals present in the films could be assigned to Cu substitutionally replacing cations in TiO₂.Facultad de Ciencias Exacta

    Experimental and ab initio study of the hyperfine parameters of ZnFe2O4 with defects

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    We present a combined Mossbauer and ab initio study on the influence of oxygen-vacancies on the hyperfine and magnetic properties of the ZnFe 2O4 spinel ferrite. Samples with different degree of oxygen-vacancies were obtained from zinc ferrite powder that was thermally treated at different temperatures up to 650 ∘C under vacuum.Theoretical calculations of the hyperfine parameters, magnetic moments and magnetic alignment have been carried out considering different defects such as oxygen vacancies and cation inversion. We show how theoretical and experimental approaches are complementary to characterize the local structure around Fe atoms and interpret the observed changes in the hyperfine parameters as the level of defects increases.Instituto de Física La Plat

    ATM activates the pentose phosphate pathway promoting anti-oxidant defence and DNA repair

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    The DNA damage-induced ATM kinase is linked to the metabolic pentose phosphate pathway, thus boosting biosynthesis of nucleotide precursors required for DNA repair and stimulating generation of the anti-oxidant NADPH, which may explain neurological defects of ataxia telangiectasia patients lacking ATM function

    Ab-initio approach to the stability and the structural, electronic and magnetic properties of the (001) Znfe₂O₄ surface terminations

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    We present a Density Functional Theory (DFT) based study of the structural and magnetic properties of the (001) surface of the semiconducting oxide Znfe₂O₄ (spinel structure). The calculations were performed using the DFT based ab initio plane wave and pseudopotential method as implemented in the Quantum Espresso code. The all electron Full-potential linearized-augmented-plane-wave method (FP-LAPW) was also employed to check the reproducibility of the plane wave method. In both calculations the DFT+U methodology was employed and different (001) surface terminations of Znfe₂O₄ were studied. We find that the surface terminated in Zn is the stable one. For all the (001) surface terminations our calculations predict that the Zn-Fe cationic inversion (antisites), which are defects in bulk Znfe₂O₄, becomes stable and an integral part of the surface. Also, a ferrimagnetic behavior is predicted for the case of anti-sites in the superficial layer. Our results for different properties of the surface of Znfe₂O₄ are compared with those obtained in bulk samples and those reported in the literature.Facultad de Ciencias ExactasInstituto de Física La Plat
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