1,523 research outputs found

    Imidazolium-based co-poly(ionic liquid) membranes for CO2/N2 separation

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    Unformatted post printThe development of efficient carbon dioxide capture and separation technologies is at the fore front of the priorities in the climate change policies. Poly(ionic liquid)s (PILs) have been emerging as extremely promising materials for the fabrication of membranes for CO2 separation. This work is a step forward to evaluate the performance of PIL-based copolymers in the preparation of membranes for CO2/N2 separation. In particular, imidazolium-based homo and copolymers were synthesized by RAFT co-polymerization of different imidazolium salts and characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) analysis. The membrane forming ability of the synthesized PILs, as well as the influence of different side chain groups (ethyl, pentyl, benzyl and napthyl) at imidazolium ring, were evaluated using the solvent casting technique. In order to improve membrane forming ability and CO2 separation performance, different amounts of free ionic liquid (IL), [C2mim][NTf2], were added into the synthesized homo and copolymers, and PIL–IL composite membranes were prepared. The CO2 and N2 permeation properties of the obtained free standing PIL–IL membranes were measured at 20 ºC and 100 kPa and the results obtained compared through the Robeson plot.K. Vijayakrishna and N. Pothanagandhi thank “International Research Staff Exchange Scheme (IRSES) 7th Framework of European Union People-2012-IRSES” (Project No: 318873), for exchange programme. K. Vijayakrishna also thank DST-SERB, India (Project NO: SR/S1/OC-22/2012) for the financial support. L.C. Tomé is grateful to FCT (Fundação para a Ciência e a Tecnologia) for her Post-doctoral research grant (SFRH/BPD/101793/2014). This work was supported by FCT through the project PTDC/CTM-POL/2676/2014 and R&D units UID/Multi/04551/2013 (GreenIT) and UID/QUI/00100/2013 (CQE). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 745734

    Dynamic critical exponents of the Ising model with multispin interactions

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    We revisit the short-time dynamics of 2D Ising model with three spin interactions in one direction and estimate the critical exponents z,z, θ,\theta, β\beta and ν\nu. Taking properly into account the symmetry of the Hamiltonian we obtain results completely different from those obtained by Wang et al.. For the dynamic exponent zz our result coincides with that of the 4-state Potts model in two dimensions. In addition, results for the static exponents ν\nu and β\beta agree with previous estimates obtained from finite size scaling combined with conformal invariance. Finally, for the new dynamic exponent θ\theta we find a negative and close to zero value, a result also expected for the 4-state Potts model according to Okano et al.Comment: 12 pages, 9 figures, corrected Abstract mistypes, corrected equation on page 4 (Parameter Q

    Mean-field analysis of the majority-vote model broken-ergodicity steady state

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    We study analytically a variant of the one-dimensional majority-vote model in which the individual retains its opinion in case there is a tie among the neighbors' opinions. The individuals are fixed in the sites of a ring of size LL and can interact with their nearest neighbors only. The interesting feature of this model is that it exhibits an infinity of spatially heterogeneous absorbing configurations for LL \to \infty whose statistical properties we probe analytically using a mean-field framework based on the decomposition of the LL-site joint probability distribution into the nn-contiguous-site joint distributions, the so-called nn-site approximation. To describe the broken-ergodicity steady state of the model we solve analytically the mean-field dynamic equations for arbitrary time tt in the cases n=3 and 4. The asymptotic limit tt \to \infty reveals the mapping between the statistical properties of the random initial configurations and those of the final absorbing configurations. For the pair approximation (n=2n=2) we derive that mapping using a trick that avoids solving the full dynamics. Most remarkably, we find that the predictions of the 4-site approximation reduce to those of the 3-site in the case of expectations involving three contiguous sites. In addition, those expectations fit the Monte Carlo data perfectly and so we conjecture that they are in fact the exact expectations for the one-dimensional majority-vote model

    C-ERB-2, P53, Ki67 proteins and receptors of estrogen and progesterone on the prognosis of epithelial ovarian cancer

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    Ovarian cancer is the seventh most common cancer diagnosed in women worldwide. To date, many studies in epithelial ovarian cancer (EOC) have reported on the association HER-2/neu, p53 proteins and steroid hormones and their respective receptors with prognosis and/or the carcinogenesis process, but no definitive conclusion has been reached. Objectives: To assess the proteins c-erbB-2, p53, Ki67 and receptors of estrogen (ER) and progesterone (PR) of EOC, with regard to clinical stage findings and its effect on survival. Methods: 125 patients with a diagnosis of EOC treated by primary surgery and chemotherapy have participated. A surgical stage was noted and analyzed the correlation with c-erbB-2, p53, Ki67, ER and PR. Immunohistochemical analysis, using the anti-c-erbB-2, p53, Ki67 monoclonal antibodies, the antibody cod PR clone PgR and code ER-6-F11 Anti human estrogen. The c-erbB-2 study was complemented by genetic amplification and was reported univariate and multivariate analysis. Results: Age 55.7 ± 16; 50.2% with residual disease (< 2 cm); initial (54.6%) and advanced (45.4%) stage. Univariate analysis showed positive staining for c-erbB-2, p-53, Ki67, PR and ER. The patients with negative receptors had a significantly shortened survival time (p = 0.01) than patients with positive receptors. Multivariable analysis revealed only clinical FIGO stage as an independent prognostic of overall survival (p = 0.002). Other variables like c-erbB-2, p53, Ki67, and ER were not significantly related to survival. Conclusions: We concluded that patients with negative PR had a significantly shortened survival time than patients with positive receptors. The overexpression of markers c-erbB-2, p53, Ki67, and ER, were not significantly related to survival in EOC. Only the FIGO stage was achieved to be an independent predictor of overall survival. They should be evaluated together with the patient’s clinical status and other prognostic factors.info:eu-repo/semantics/publishedVersio

    Impact of MOF-5 on pyrrolidinium-based poly(ionic liquid)/ionic liquid membranes for biogas upgrading

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    PostprintBearing in mind that Metal Organic Frameworks (MOFs) have remarkable CO2 adsorption selectivity and Mixed Matrix Membranes (MMMs) have been identified as potential solution for advancing the current state of the art of membrane separation technology, this work investigates the effect of combining a MOF, with high adsorption properties towards CO2 when compared to CH4 (MOF-5), with a blend of poly(ionic liquid)/ionic liquid (PIL/IL) for biogas upgrading. The blend system consisted of a pyrrolidinium-based PIL, poly([Pyr11][Tf2N]), and a free imidazolium-based IL, [C2mim][BETI]. The MOF-5 was incorporated at different loadings (10, 20, 30 wt%), and MMMs were prepared by solvent evaporation technique and characterized by diverse techniques (FTIR, SEM, TGA, puncture tests, water contact angle and single gas transport). The results showed that the free IL is miscible with the PIL, while MOF-5 particles were uniformly dispersed into the PIL/IL matrix. The formed PIL/IL/MOF-5 membranes revealed suitable thermal stability (Tonset up to 656 K) for biogas upgrading processes, but a loss of mechanical stability was found after the incorporation of MOF-5, and thus more rigid and fragile membranes were obtained. Besides, increasing MOF-5 content in the MMMs resulted in improved CO2 permeability. At 30 wt% of MOF-5 loading the CO2 permeability increased 133% when compared to that of the pristine PIL/IL membrane, while the ideal selectivity CO2/CH4 decreases. It was possible to demonstrate the relevance of studying different components within the polymeric matrix in order to assess not only thermal, mechanical and chemical properties, but also gas transport response.This work was supported by FCT (Fundação para Ciência e a Tecnologia) through the project PTDC/CTM-POL/2676/2014 and the Associate Laboratory for Green Chemistry - LAQV (UID/QUI/50006/2019). Ana R. Nabais and Luísa A. Neves are grateful to FCT/MCTES for their PhD grant (SFRH/BD/136963/2018) and FCT Investigador Contract (IF/00505/2014), respectively. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 745734

    Validation of 3-day rainfall forecast at the regional scale

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    Nearly half of the natural disasters in the world are due to hydro-geomorphological hazards. Therefore, rainfall forecast is a key parameter for the implementation of landslides and flash-floods early warning systems. In this work we developed a routine in R software that enables the validation of a 3-day rainfall forecast by comparison with the daily rainfall data recorded in 101 automatic meteorological stations available in mainland Portugal. The routine integrates the pre-processing of base data, the matching between the 3-day rainfall forecast and the daily rainfall registered in the automatic meteorological stations based on sequence of days, the estimation of the difference between the forecasted and the real rainfall values and the computation of error measures, such as the bias, the mean absolute error, the mean absolute percentage error and the root mean square error. The results from the error measures, estimated for the 101 automatic meteorological stations, are then exported to an excel file. The routine is implemented for mainland Portugal and tested using data from February 2015, however, the spatial and temporal data can be easily updated for other regions

    The restitution of an oxalate-damaged epithelium

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    The renal inner medulla is responsible for the hydro-saline equilibrium maintenance through water and electrolyte excretionin urine. The collecting ducts, which are involved in the urine concentration, are immersed in an extracellular matrix with thehighest body osmolarity. The hyperosmolarity is a key signal for cell differentiation and for the establishment of the urineconcentration mechanism. Moreover, renal ducts are exposed to wastes coming from blood filtration. There are severalnephrotoxic agents such as antibiotics, diuretics, antineoplastic and cytostatic agents, and renal stones. Calcium oxalate stonesare the most common type of kidney stone. The crystal aggregates are harmful for epithelial renal cells and tubular structures,and that damage could lead to the development of chronic kidney disease. Our previous results showed that differentiated renalcells treated with oxalate (Ox) for 24 h lost the typical epithelial cobblestone morphology and showed a spindle-shapedmorphology characteristic of an epithelial mesenchymal transition. After 48 h of Ox, cells started to recover their morphologyand after 72 h of Ox the epithelium was almost reestablished. The aims of the present work were to evaluate whether epithelialintegrity is disrupted after 24 h of Ox and whether epithelial differentiated characteristics are restituted after 72 h of Ox. Todo that, the renal epithelial cells MDCK were grown in a hyperosmolar environment (512 mOsm/Kg H2O) for 72 h to get adifferentiated epithelium, and then subjected to 1.5 mM Ox for 24, 48 and 72 h. After treatments, cell morphology and theexpression of differentiated epithelia markers were evaluated by fluorescence microscopy. E-cadherin, a member of adherensjunctions, was localized to the cell periphery at 24, 48 and 72 h in control conditions. After 24 h of Ox, the protein wasinternalized and its label on the periphery decreased. After 48 h of Ox, E-cadherin was localized both to the cell membranesand to the cytoplasm, while after 72 h of Ox the label was mainly at the cell periphery. In control cells the apical marker gp135was localized at apical cell surface, while in cells treated with 24 h of Ox gp135 apical staining was reduced. After 48 h of Ox,the percentage of cells expressing apical gp135 started to increase reaching values like control conditions at 72 h. Finally,primary cilium was evidenced by acetylated-tubulin immunofluorescence. Control cells showed a high percentage of ciliatedcells, while it decreased upon treatment with 24 h of Ox. After 48 h of Ox, the cells started to recover the primary cilium, andafter 72 h of Ox, the percentage of ciliated cells reached control values. The results showed that the treatment with 24 h of Oxinduces dedifferentiation and after 72 h of the cell damage there is a restitution of the differentiated epithelia. The next goal isto elucidate the molecular mechanisms involved in the restitution of the oxalate-damaged epithelium.Fil: Sendyk, Dylan. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Biología Celular y Molecular; ArgentinaFil: Pescio, Lucila Gisele. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Biología Celular y Molecular; ArgentinaFil: Fernández Tomé, M. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Biología Celular y Molecular; ArgentinaFil: Casali, Cecilia Irene. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Ciencias Biológicas. Cátedra de Biología Celular y Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Físico-Química Biológicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Físico-Química Biológicas; ArgentinaLVII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research and XVI Annual Meeting of the Argentinean Society for General MicrobiologyVirtualArgentinaSociedad Argentina de Investigación Bioquímica y Biología MolecularAsociación Civil de Microbiología Genera

    Validation of 3-day rainfall forecast at the regional scale

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    Nearly half of the natural disasters in the world are due to hydro-geomorphological hazards. Therefore, rainfall forecast is a key parameter for the implementation of landslides and flash-floods early warning systems. In this work we developed a routine in R software that enables the validation of a 3-day rainfall forecast by comparison with the daily rainfall data recorded in 101 automatic meteorological stations available in mainland Portugal. The routine integrates the pre-processing of base data, the matching between the 3-day rainfall forecast and the daily rainfall registered in the automatic meteorological stations based on sequence of days, the estimation of the difference between the forecasted and the real rainfall values and the computation of error measures, such as the bias, the mean absolute error, the mean absolute percentage error and the root mean square error. The results from the error measures, estimated for the 101 automatic meteorological stations, are then exported to an excel file. The routine is implemented for mainland Portugal and tested using data from February 2015, however, the spatial and temporal data can be easily updated for other regions. • A routine to validate the rainfall forecast at the regional scale using R programming language is implemented. • The automated routine can be easily updated and adapted with different spatial and temporal scales

    Anorectal Complications in Patients with Haematological Malignancies

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    Background: Anorectal complications are common in patients with haematological malignancies. Objectives: The objectives are to characterize anorectal complications in these patients, identify risk factors and shed light on treatment, morbidity and mortality rates. Patients and methods: A retrospective, observational study that included 83 inpatients with haematological malignancies and proctological symptoms from January 2010 to September 2015 was conducted. Clinical outcomes were obtained through a detailed review of medical records. Results: The median age was 56 years, and 52 (62.7%) patients were men. Fifty-six (67.5%) patients had nonseptic anorectal complications and 27 (32.5%) patients had septic anorectal complications. Risks factors: Patients with septic anorectal complications were more commonly male, older, and had lower absolute neutrophil counts, but the differences were not statistically significant (P=0.79, 0.67 and 0.89, respectively). In positive blood cultures [23/70 (32.9%)], Enterococcus faecium, Klebsiella pneumonia, and Escherichia coli were the most common isolated agents. Treatment: In nonseptic anorectal complications, conservative treatments/minor proctological procedures were adopted, and patients with septic anorectal complications were treated with antibiotics±major proctological procedures and/or surgical drainage/debridement. Results of treatment: Forty-eight (85.7%) patients in the nonseptic complications group improved compared with 23 (85.2%) patients in the septic complications group. The overall mortality rate was 2.4% (n=2), with one (1.2%) death related to perianal sepsis. Conclusion: Enterococcus spp. were more commonly identified in this study and can be increasing in this specific population. In contrast to other reports, we did not identify an association between septic anorectal complications and possible risk factors such as male sex, younger age or a low absolute neutrophil count. Most patients had nonseptic anorectal complications. A major proctological procedure/surgical debridement should always be applied in septic complications, which have better prognoses now than in the past.info:eu-repo/semantics/publishedVersio

    Brain connectivity analysis: a short survey

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    This short survey the reviews recent literature on brain connectivity studies. It encompasses all forms of static and dynamic connectivity whether anatomical, functional, or effective. The last decade has seen an ever increasing number of studies devoted to deduce functional or effective connectivity, mostly from functional neuroimaging experiments. Resting state conditions have become a dominant experimental paradigm, and a number of resting state networks, among them the prominent default mode network, have been identified. Graphical models represent a convenient vehicle to formalize experimental findings and to closely and quantitatively characterize the various networks identified. Underlying these abstract concepts are anatomical networks, the so-called connectome, which can be investigated by functional imaging techniques as well. Future studies have to bridge the gap between anatomical neuronal connections and related functional or effective connectivities
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