Efecto del tiempo de superpulso de soldadura sobre la evolución microestructural de un acero de bajo carbono

El tipo de arco Súper Pulso fue desarrollado para proporcionar una solución a los cordones de pasada de raíz de juntas a tope, en el proceso de soldadura semiautomático con protección gaseosa (GMAW). A diferencia de la soldadura por pulsos estándar, el Súper Pulso utiliza una secuencia de diferentes formas de onda de pulso para crear una forma y aspecto de cordón similar al proceso GTAW. Utiliza bajo amperaje en la fase primaria para reducir el calor aportado y más alto amperaje en la segunda fase para mejorar la penetración. La velocidad de soldadura e incluso la penetración se proporcionan durante la fase de transferencia en spray, mientras que la entrada de calor se reduce durante la segunda fase (transferencia en corto, arco corto o pulsado). Se utiliza la transferencia de spray en la fase primaria para mejorar la penetración y arco pulsado en la fase secundaria para enfriar el baño de soldadura dando menos transferencia de calor y menos distorsión al material de base. En la literatura hay poca información respecto a la relación entre las variables del Súper Pulso y las características microestructurales del metal depositado. El objetivo de este trabajo fue evaluar la influencia de los tiempos de cada fase en modo Súper Pulso, sobre las características geométricas del cordón, la dilución y la solidificación en depósitos de soldadura de aceros con bajo contenido de carbono. Para tal fin, se soldaran cordones sobre una chapa IRAM - IAS U500 - 42 - F24 variando el tiempo de fases del Súper Pulso. Sobre cortes transversales se determinó la geometría de los cordones, el grado de dilución, la microestructura y sobre cortes longitudinales las características de las zonas fundidas y afectadas. Resultados preliminares mostraron que la geometría del cordón y la solidificación estuvieron fuertemente influenciadas por los parámetros del pulso.Superpulse system was a motivation to provide a GMAW solution for root pass on steel. Unlike standard pulse welding, pulse/pulse (superpulse) uses a sequence of varying pulse wave shapes to create a bead shape and appearance similar to the GTAW process. It utilizes low amperage in the primary phase for heat reduction and higher amperage in the second phase for enhanced penetration. The welding speed and even penetration are provided during the spray arc phase, whereas heat input is reduced during pulse phase. It utilises spray arc transfer in the primary phase for enhanced penetration and pulse arc in the secondary phase, which serves to cool the weld pool for less heat transfer to the base material and less distortion. Pulsing in the second phase also allows spray type transfer to be achieved in all positions of welding. Nowadays there is scare information about the relationship between variables of procedure and microstructural characteristics of the weld metal. Therefore the aim of this work was to evaluate the influence of pulse time on the dilution and solidification of F24 steel plate. For this purpose, four coupons modifying the time of pulse were welded. On each coupon, chemical composition was determined and microstructure was studied using both optical and electronic microscopy. The dilution and microhardness of beads and phases were measured. Preliminary results show that the geometry of the bead and the solidification were strongly influenced by the pulse parameters

Primary hyperparathyroidism diagnosed after surgical ablation of a costal mass mistaken for giant-cell bone tumor: a case report

<p>Abstract</p> <p>Introduction</p> <p>Primary hyperparathyroidism is a common endocrine disorder characterized by elevated parathyroid hormone levels, which cause continuous osteoclastic bone resorption. Giant cell tumor of bone is an expansile osteolytic tumor that contains numerous osteoclast-like giant cells. There are many similarities in the radiological and histological features of giant cell tumor of bone and brown tumor. This is a rare benign focal osteolytic process most commonly caused by hyperparathyroidism.</p> <p>Case presentation</p> <p>We report the unusual case of a 40-year-old Caucasian woman in which primary hyperparathyroidism was diagnosed after surgical ablation of a costal mass. The mass was suspected of being neoplastic and histopathology was compatible with a giant cell tumor of bone. On the basis of the biochemical results (including serum calcium, phosphorous and intact parathyroid hormone levels) primary hyperparathyroidism was suspected and a brown tumor secondary to refractory hyperparathyroidism was diagnosed.</p> <p>Conclusions</p> <p>Since giant cell tumor is a bone neoplasm that has major implications for the patient, the standard laboratory tests in patients with bone lesions are important for a correct diagnosis.</p

Mda-9/Syntenin Is Expressed in Uveal Melanoma and Correlates with Metastatic Progression

Uveal melanoma is an aggressive cancer that metastasizes to the liver in about half of the patients, with a high lethality rate. Identification of patients at high risk of metastases may provide indication for a frequent follow-up for early detection of metastases and treatment. The analysis of the gene expression profiles of primary human uveal melanomas showed high expression of SDCBP gene (encoding for syndecan-binding protein-1 or mda-9/syntenin), which appeared higher in patients with recurrence, whereas expression of syndecans was lower and unrelated to progression. Moreover, we found that high expression of SDCBP gene was related to metastatic progression in two additional independent datasets of uveal melanoma patients. More importantly, immunohistochemistry showed that high expression of mda-9/syntenin protein in primary tumors was significantly related to metastatic recurrence in our cohort of patients. Mda-9/syntenin expression was confirmed by RT-PCR, immunofluorescence and immunohistochemistry in cultured uveal melanoma cells or primary tumors. Interestingly, mda-9/syntenin showed both cytoplasmic and nuclear localization in cell lines and in a fraction of patients, suggesting its possible involvement in nuclear functions. A pseudo-metastatic model of uveal melanoma to the liver was developed in NOD/SCID/IL2Rγ null mice and the study of mda-9/syntenin expression in primary and metastatic lesions revealed higher mda-9/syntenin in metastases. The inhibition of SDCBP expression by siRNA impaired the ability of uveal melanoma cells to migrate in a wound–healing assay. Moreover, silencing of SDCBP in mda-9/syntenin-high uveal melanoma cells inhibited the hepatocyte growth factor (HGF)-triggered invasion of matrigel membranes and inhibited the activation of FAK, AKT and Src. Conversely syntenin overexpression in mda-9/syntenin-low uveal melanoma cells mediated opposite effects. These results suggest that mda-9/syntenin is involved in uveal melanoma progression and that it warrants further investigation as a candidate molecular marker of metastases and a potential therapeutic target

Genome-wide association studies of autoimmune vitiligo identify 23 new risk loci and highlight key pathways and regulatory variants

Vitiligo is an autoimmune disease in which depigmented skin results from the destruction of melanocytes1, with epidemiological association with other autoimmune diseases2. In previous linkage and genome-wide association studies (GWAS1 and GWAS2), we identified 27 vitiligo susceptibility loci in patients of European ancestry. We carried out a third GWAS (GWAS3) in European-ancestry subjects, with augmented GWAS1 and GWAS2 controls, genome-wide imputation, and meta-analysis of all three GWAS, followed by an independent replication. The combined analyses, with 4,680 cases and 39,586 controls, identified 23 new significantly associated loci and 7 suggestive loci. Most encode immune and apoptotic regulators, with some also associated with other autoimmune diseases, as well as several melanocyte regulators. Bioinformatic analyses indicate a predominance of causal regulatory variation, some of which corresponds to expression quantitative trait loci (eQTLs) at these loci. Together, the identified genes provide a framework for the genetic architecture and pathobiology of vitiligo, highlight relationships with other autoimmune diseases and melanoma, and offer potential targets for treatment

Sex- and age-related differences in the management and outcomes of chronic heart failure: an analysis of patients from the ESC HFA EORP Heart Failure Long-Term Registry

Aims: This study aimed to assess age- and sex-related differences in management and 1-year risk for all-cause mortality and hospitalization in chronic heart failure (HF) patients. Methods and results: Of 16 354 patients included in the European Society of Cardiology Heart Failure Long-Term Registry, 9428 chronic HF patients were analysed [median age: 66 years; 28.5% women; mean left ventricular ejection fraction (LVEF) 37%]. Rates of use of guideline-directed medical therapy (GDMT) were high (angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, beta-blockers and mineralocorticoid receptor antagonists: 85.7%, 88.7% and 58.8%, respectively). Crude GDMT utilization rates were lower in women than in men (all differences: P\ua0 64 0.001), and GDMT use became lower with ageing in both sexes, at baseline and at 1-year follow-up. Sex was not an independent predictor of GDMT prescription; however, age >75 years was a significant predictor of GDMT underutilization. Rates of all-cause mortality were lower in women than in men (7.1% vs. 8.7%; P\ua0=\ua00.015), as were rates of all-cause hospitalization (21.9% vs. 27.3%; P\ua075 years. Conclusions: There was a decline in GDMT use with advanced age in both sexes. Sex was not an independent predictor of GDMT or adverse outcomes. However, age >75 years independently predicted lower GDMT use and higher all-cause mortality in patients with LVEF 6445%

Granulysin, a novel marker for extranodal NK/T cell lymphoma, nasal type

Granulysin is a cytolytic protein expressed in cytotoxic T and natural killer (NK) cells. Abnormal serum levels of granulysin in lymphomas with NK and cytotoxic phenotype have been shown to correlate with tumour progression. In this study, we investigated the expression pattern of granulysin in routine sections of normal and reactive lymphoid tissues as well as in a large series of lymphomas. In normal tissues, granulysin labelled a small population of cells that double immunostaining revealed to belong to the pool of cytotoxic T/NK cells. Among lymphoid neoplasms, the highest expression of granulysin (71%) was found in extranodal NK/T cell lymphomas of nasal type (ENKTL). To note is that 29% of ENKTLs, which were negative for one or more of classical cytotoxic markers strongly expressed granulysin. Furthermore, expression of granulysin was observed in rare cases of T cell lymphomas with a cytotoxic phenotype (i.e. ALK-negative anaplastic large cell lymphoma (26%), enteropathy-associated T cell lymphoma (12%) and peripheral T cell lymphoma, NOS (4%)). None of the investigated non-Hodgkin B cell lymphomas, Hodgkin lymphoma and plasma cell myeloma were granulysin positive. The results suggest granulysin as a novel marker for a subset of cytotoxic NK cell derived malignancies and its usefulness is highlighted in those ENKTLs that lack expression of other cytotoxic markers but retain granulysin expression