Estructuras de titanio porosas, fabricación y caracterización

Fil: Lopez Padilla, R. M. Universidad Tecnológica Nacional. Facultad Córdoba. Departamento de Metalurgia; Argentina.Fil: Oldani, C. R. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento Materiales; Argentina.Fil: Grinschpun, L. S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento Materiales; Argentina.Fil: Lucci, R. O. Universidad Tecnológica Nacional. Facultad Córdoba. Departamento de Metalurgia; Argentina.Para la obtención de estructuras de titanio porosas se estudió el proceso de partículas espaciadoras, que consiste en mezclar los polvos a sinterizar con uncomponente que volatiliza a bajas temperaturas, en este caso el carbonato ácido de amonio, y que al hacerlo deja espacios vacíos (poros) en la estructura. Seobtuvieron compactos de titanio con porosidad abierta entre 35% y 72% y tamaño de poro entre 200 mm y 300 mm. Además se efectuaron estudios iniciales defabricación de compactos de titanio con gradiente de porosidad mediante compactación secuencial, a fin de obtener valores de módulo de elasticidaddiferenciado entre la superficie y el centro comparables a los que se observan en los huesos.Se caracterizaron los compactos porosos obtenidos mediante microscopía óptica y electrónica para evaluar la microestructura y a través de ensayos decompresión para determinar los valores de límite de fluencia y módulo de elasticidad.Se determinó la influencia de los principales parámetros del proceso; porcentaje y granulometría de las partículas espaciadoras, presión de compactación,temperatura y tiempo de sinterización, sobre los valores de módulo de elasticidad, límite de fluencia y microestructura. Los resultados obtenidos indican que esposible ajustar los valores de módulo de elasticidad y límite de fluencia de los compactos porosos de titanio producidos, de manera que se asemejen a los queposeen tanto los huesos trabeculares como corticales. Además, se pueden adecuar las porosidades alcanzadas, a los valores indicados en la bibliografía, comoaquellos que satisfacen las necesidades de vascularización y transporte de productos metabólicos que son fundamentales en la formación del tejido óseo. El rangode tamaño de poro alcanzado se encuentra dentro de los valores recomendados, para una correcta integración del material poroso con el hueso alojante ya quepermiten una buena migración y adhesión celular.Fil: Lopez Padilla, R. M. Universidad Tecnológica Nacional. Facultad Córdoba. Departamento de Metalurgia; Argentina.Fil: Oldani, C. R. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento Materiales; Argentina.Fil: Grinschpun, L. S. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Departamento Materiales; Argentina.Fil: Lucci, R. O. Universidad Tecnológica Nacional. Facultad Córdoba. Departamento de Metalurgia; Argentina.Ingeniería de los Materiale

Tuberculosis and airflow obstruction: evidence from the PLATINO study in Latin America

The aim of the present study was to evaluate the association between history of tuberculosis and airflow obstruction.A population-based, multicentre study was carried out and included 5,571 subjects aged >= 40 yrs living in one of five Latin American metropolitan areas: São Paulo (Brazil); Montevideo (Uruguay); Mexico City (Mexico); Santiago (Chile); and Caracas (Venezuela). Subjects performed pre- and post-bronchodilator spirometry and were asked whether they had ever been diagnosed with tuberculosis by a physician.The overall prevalence of airflow obstruction (forced expiratory volume in one second/forced vital capacity post-bronchodilator < 0.7) was 30.7% among those with a history of tuberculosis, compared with 13.9% among those without a history. Males with a medical history of tuberculosis were 4.1 times more likely to present airflow obstruction than those without such a diagnosis. This remained unchanged after adjustment for confounding by age, sex, schooling, ethnicity, smoking, exposure to dust and smoke, respiratory morbidity in childhood and current morbidity. Among females, the unadjusted and adjusted odds ratios were 2.3 and 1.7, respectively.In conclusion, history of tuberculosis is associated with airflow obstruction in Latin American middle-aged and older adults.Univ Fed Pelotas, BR-96020220 Pelotas, BrazilUniversidade Federal de São Paulo, São Paulo, BrazilNatl Inst Resp Dis, Mexico City, DF, MexicoUniv Republica, Montevideo, UruguayCatholic Univ Chile, Santiago, ChileCent Univ Venezuela, Caracas, VenezuelaUniversidade Federal de São Paulo, São Paulo, BrazilWeb of Scienc

Quasars probing intermediate redshift star-forming galaxies

We present a sample of 46 [OIII]-emitting galaxies at z<0.8 detected in the fibre spectra of quasars from the SDSS-DR7 through an automatic search procedure. We also detect [OII] and Hb emission lines from most of these galaxies in the SDSS spectra. We study both the emission and absorption properties of a sub-sample of 17 galaxies in the redshift range z=0.4-0.7, where MgII lines are covered by the SDSS spectra. The measured lower-limits on the star-formation rates of these galaxies are in the range 0.2-20 M_sun/yr. The emission line luminosities and (O/H) metallicities from R23 measured in this sample are similar to what is found in normal galaxies at these redshifts. Thus, this constitutes a unique sample of intermediate redshift star-forming galaxies where we can study the QSO absorber - galaxy connection. Strong MgII (W>1A) as well as MgI absorption lines are detected in the QSO spectra at the redshift of most of these galaxies. Strong FeII (W>1A) absorption lines are also generally detected whenever the appropriate wavelength ranges are covered. This suggests that most of these systems could be bona-fide Damped Lyman-alpha systems. We investigate various possible relations between the MgII rest equivalent widths and the emission line properties. We find a possible (2 sigma) correlation between the emission-line metallicity of the galaxies and the MgII rest equivalent width of the absorbers [truncated].Comment: 15 pages, 11 figures, 5 tables. accepted for publication in MNRA

Functional effect of miR-1307-3p on breast cancer progression

Background: MiRNAs are non-coding RNA molecules and its function is the regulation of gene expression. In cancer, the deregulation of miRNAs allows them to act as oncogenes or tumor suppressors. From an analysis of the expression of miRNAs in breast cancer (BC) in The Cancer Genome Atlas (TCGA), it was identified that miR-1307-3p is significantly overexpressed in the tumor tissue compared to healthy tissue from patients. So far, in BC, it has only been reported that this miRNA inhibits SMYD4 and that it is involved in resistance to cisplatin through its effect on Mdm4. In this project we propose to identify the role of miR-1307-3p in proliferation, migration, invasion, angiogenesis, and possible targets involved in these processes in BC cells. Methods: RT-qPCR was used to evaluate basal levels of miR-1307-3p in the BC cell lines MDA-MB-231 and MCF-7, and the human epithelial breast MCF-10A cells. Later, we determined the effect of miR-1307-3p on proliferation, migration, and invasion in MDA-MB-231 and MCF-7, and angiogenesis in the HUVEC endothelial cells. All assays were carried out using the miR-1307-3p inhibitor. Then, nine miRNA-target prediction databases were analyzed to identify potential miR-1307-3p target genes, and their expression was analyzed by RT-qPCR in a designed 384-well plate. Finally, the targets that presented an alteration in their expression were evaluated by western blot. Results: We found that miR-1307-3p is overexpressed in MDA-MB-231 and MCF-7, compared to MCF-10A cells. We also identified that transfection with the miR-1307-3p inhibitor causes a significant decrease in the processes of proliferation, migration, invasion, and angiogenesis, when compared with untreated or negative control transfected cells. For its part, prediction databases analysis allowed us to identify 19 potential targets of miR-1307-3p. We also found that 2 genes were overexpressed, CIC and PRM2. Finally, we found an overexpression of PRM2 protein. Conclusions: MiR-1307-3p is overexpressed in BC cells. Furthermore, miR-1307-3p induces the processes of proliferation, migration and invasion in BC cells, and angiogenesis in HUVEC cells. These observations suggest that miR-1307-3p can acts as an onco-miRNA. In addition, a potential new target of miR-1307-3p was found, PRM2 which has not been previously reported in breast cancer. Further analysis to verify and validate the implication of this miR-1307-3p target are needed to understand its importance in BC

Effect of miR-660-5p in breast cancer progression

Background: Breast cancer (BC) is the most diagnosed cancer in women worldwide. MicroRNAs (miRNAs) participate in different processes of BC and their deregulation can cause them to act as oncogenes or tumor suppressors, participating in cancer progression. Using the TCGA (The Cancer Genome Atlas) database, we found that miR-660-5p significantly overexpressed and associated with poor survival in patients with this pathology. Moreover, it is reported that miR-660-5p can induce BC progression through transcription factor CP2 (TFCP2) and the downregulation of tet methylcytosine dioxygenase 2 (TET2). In this project, we propose to identify the role of miR-660-5p in proliferation, migration, invasion, angiogenesis, and the possible targets involved in these processes in BC cell lines. Methods: Basal levels of miR-660-5p were determined in BC cells MDA-MB-231 and MCF-7, and in human epithelial breast cells MCF-10A by RT-qPCR. The effect of miR-660-5p was evaluated on proliferation, migration, and invasion processes in MDA-MB-231 and MCF-7 cells. HUVEC cells were used to assess angiogenesis. All cell lines were transfected with miR-660-5p inhibitor. Analysis of nine miRNA-target prediction databases was made to identify targets of miR-660-5p. We selected the targets genes predicted by at least three of these programs, and their expression were evaluated in MDA-MB-231 cells by RT-qPCR in a customized plate. We validated those results with Western blot. Results: We found that miR-660-5p is significantly upregulated in MDA-MB-231 and MCF-7, compared to MCF-10A cells. In addition, we observed a significant decrease in proliferation, migration, and invasion in BC cells transfected with miR-660-5p inhibitor, compared to nontreated cells and miRNA inhibitor negative control cells. Similarly, we observed a significant decrease in angiogenesis of HUVEC cells transfected with miR-660-5p inhibitor. Furthermore, of all the miR-660-5p target genes identified by prediction databases, 17 were selected, and of these, three were observed upregulated and one downregulated. We found that CD8A, LIFR and TMEM41B are reported as tumor suppressors in different types of cancer. We validated those results by Western blot, observing an increase in TMEM41B protein levels in the group of cells transfected with miR-660 inhibitor compared to nontreated cells and miRNA inhibitor negative control cells. Conclusions: The results show that miR-660-5p is upregulated and involved in proliferation, migration, invasion, and angiogenesis of BC, which may lead us to suggest that this miRNA act as an onco-miRNA. In addition, we found that TMEM41B could be a potential target of miR-660-5p

MAGIC upper limits on the very high energy emission from GRBs

The fast repositioning system of the MAGIC Telescope has allowed during its first data cycle, between 2005 and the beginning of year 2006, observing nine different GRBs as possible sources of very high energy gammas. These observations were triggered by alerts from Swift, HETE-II, and Integral; they started as fast as possible after the alerts and lasted for several minutes, with an energy threshold varying between 80 and 200 GeV, depending upon the zenith angle of the burst. No evidence for gamma signals was found, and upper limits for the flux were derived for all events, using the standard analysis chain of MAGIC. For the bursts with measured redshift, the upper limits are compatible with a power law extrapolation, when the intrinsic fluxes are evaluated taking into account the attenuation due to the scattering in the Metagalactic Radiation Field (MRF).Comment: 25 pages, 9 figures, final version accepted by ApJ. Changet title to "MAGIC upped limits on the VERY high energy emission from GRBs", re-organized chapter with description of observation, removed non necessaries figures, added plot of effective area depending on zenith angle, added an appendix explaining the upper limit calculation, added some reference

Invasive Pulmonary Adenocarcinoma with Lepidic Growth Pattern in a Pregnant Patient

Among the differential diagnoses that should be considered in acute respiratory failure (ARF) are infectious processes, autoimmune diseases, interstitial pulmonary fibrosis, and pulmonary neoplasia. Timely diagnosis of lung neoplasia is complicated in the early stages. An opportune diagnosis, as well as the specific treatment, decrease mortality. ARF occurs 1 in 500 pregnancies and is most common during the postpartum period. Among the specific etiologies that cause ARF during pregnancy that must be considered are: (1) preeclampsia; (2) embolism of amniotic fluid; (3) peripartum cardiomyopathy; and (4) trophoblastic embolism. The case of a 36-year-old patient with a 33-week pregnancy and ARF is presented. The patient presented dyspnea while exerting moderate effort that progressed to orthopnea and type 1 respiratory insufficiency. Imaging studies showed bilateral alveolar infiltrates and predominantly right areas of consolidation. Blood cultures, a galactomannan assay and IgG antibodies against mycoplasma pneumoniae, were reported as negative. Autoimmune etiology was ruled out through an immunoassay. A percutaneous pulmonary biopsy was performed and an invasive pulmonary adenocarcinoma with lepidic growth pattern (i.e. lepidic pulmonary adenocarcinoma, LPA) result was reported. This etiology is rare and very difficult to recognize in acute respiratory failure cases. After infectious, autoimmune and interstitial lung fibrosis have been excluded the clinician must suspect of lung cancer in a patient with acute respiratory failure and chest imaging compatible with the presence of ground-glass nodular opacities, a solitary nodule or mass with bronchogram, and lung consolidation. In the presence of acute respiratory failure, the suspicion of pulmonary neoplasia in an adult of reproductive age must be timely. Failure to recognize this etiology can lead to fatal results

Bi-allelic variants in RNF170 are associated with hereditary spastic paraplegia.

Alterations of Ca2+ homeostasis have been implicated in a wide range of neurodegenerative diseases. Ca2+ efflux from the endoplasmic reticulum into the cytoplasm is controlled by binding of inositol 1,4,5-trisphosphate to its receptor. Activated inositol 1,4,5-trisphosphate receptors are then rapidly degraded by the endoplasmic reticulum-associated degradation pathway. Mutations in genes encoding the neuronal isoform of the inositol 1,4,5-trisphosphate receptor (ITPR1) and genes involved in inositol 1,4,5-trisphosphate receptor degradation (ERLIN1, ERLIN2) are known to cause hereditary spastic paraplegia (HSP) and cerebellar ataxia. We provide evidence that mutations in the ubiquitin E3 ligase gene RNF170, which targets inositol 1,4,5-trisphosphate receptors for degradation, are the likely cause of autosomal recessive HSP in four unrelated families and functionally evaluate the consequences of mutations in patient fibroblasts, mutant SH-SY5Y cells and by gene knockdown in zebrafish. Our findings highlight inositol 1,4,5-trisphosphate signaling as a candidate key pathway for hereditary spastic paraplegias and cerebellar ataxias and thus prioritize this pathway for therapeutic interventions